Condition Analysis
AI-powered assessment using site data and 14-day weather history
The heavy 27.7mm rainfall on May 3rd was followed by only a few days of modest drying conditions, with light precipitation on May 4th and today (May 7th), and the rock is very likely still holding significant internal moisture. With further rain forecast over the next several days, conditions are not suitable for climbing on gritstone.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Brimham's mixed aspects mean south-facing formations will have dried faster since May 3rd, but north-facing towers and shaded gullies between formations will still be retaining moisture from the heavy soaking.
- The scattered boulder and tower formations create sheltered micro-environments where wind — despite the exposed moorland setting — cannot reach all surfaces equally, leaving leeward faces and recessed cracks damp longer.
- The open moorland at 290m means overnight temperatures have been dropping to low single digits (2–4°C), significantly slowing the evaporation rate during the long overnight hours.
- The cumulative 49.8mm over the past 28 days indicates the rock has been repeatedly wetted without extended drying windows, meaning the deeper pore structure is likely near-saturated even where surfaces appear dry.
Warnings
2
- The rock surface may appear dry on south-facing formations while the interior remains dangerously saturated from the 27.7mm event on May 3rd — do not trust surface appearance alone.
- Climbing on wet gritstone causes permanent, irreversible damage to holds and routes at Brimham, a nationally important site managed by the National Trust.
Reasoning
The 27.7mm deluge on May 3rd would have deeply saturated the gritstone, and with only ~3.5 days of imperfect drying (including 0.3mm on May 4th and 0.2mm today), the rock almost certainly retains significant internal moisture well above the 1% threshold for strength loss.
Moderate winds (16–21 km/h) and temperatures around 9–13°C have provided some drying on exposed south-facing surfaces, but humidity averaging 78% over the past week and cool overnight lows have severely limited evaporation — after 27.7mm, at least 72+ hours of good drying is needed, and conditions have been far from ideal.
With the pore structure likely still substantially saturated from the May 3rd event compounded by repeated wetting over the past month, climbing risks hold breakage and grain loosening on a rock type already vulnerable to wet-state strength loss of 10–50%.
Spring conditions in early May at 290m remain marginal — cool temperatures, high humidity, and frequent precipitation events mean the rock has had very few genuine drying windows since winter.
Contributing Factors
6
The 27.7mm on May 3rd was the most significant single-day rainfall in the dataset and would have deeply saturated the porous gritstone.
Only 3–4 days have elapsed since the heavy rain, with additional light precipitation on May 4th and today limiting effective drying hours.
Nearly 50mm over the past 28 days with frequent wetting events means the rock has been repeatedly re-saturated without adequate recovery periods.
Brimham's exposed moorland position and winds of 15–21 km/h have aided surface drying on windward faces since May 3rd.
Average temperatures of ~9°C over the past week with overnight lows near 2–5°C significantly slow evaporation rates.
Over 10mm of rain is forecast across the next 5 days, preventing any meaningful extended drying window from developing.
Recommendations
3
- Wait for an extended dry spell of at least 3–4 consecutive days with good winds and temperatures above 10°C before visiting — the current forecast does not offer this window.
- If you do visit, check the ground at the base of formations: if the soil or peat is damp, the rock is almost certainly still wet internally.
- Consider alternative non-porous venues (limestone, whinstone) if you need a climbing fix this week.
Previous Analyses
Marginal — Assess Conditions
55%
2 days ago
Heavy rain on May 3rd (27.7mm) was followed by only two full dry days and modest drying conditions; south-facing and exposed formations may be dry enough to climb but north-facing and sheltered features are likely still damp internally. Climbers should visually and physically assess rock conditions on arrival before committing, and avoid north-facing or low-lying sections.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Brimham's formations are freestanding towers and pinnacles with all aspects, meaning south-facing sides will have dried significantly faster than north-facing sides of the same boulder — check each feature individually.
- The exposed moorland position and moderate winds (15–20 km/h) over the past two days have aided surface drying, but the 27.7mm deluge on May 3rd represents serious saturation for porous gritstone.
- Many of Brimham's popular problems are on sheltered undersides of balanced rocks and overhanging faces, which paradoxically dry faster (less direct rain exposure) but can also harbour seepage from above.
- National Trust site with permissive access — climbing on visibly damp gritstone risks both route damage and access restrictions; err on the side of caution to protect this unique venue.
Warnings
2
- The 27.7mm soaking on May 3rd is borderline for only 48 hours of drying — gritstone can appear surface-dry while retaining dangerous internal moisture that weakens holds.
- Overnight temperatures near 0°C on recent mornings may have caused minor freeze-thaw stress on still-saturated rock; be wary of any holds that sound hollow or feel gritty.
Reasoning
The 27.7mm rainfall on May 3rd would have deeply saturated the gritstone, and with only two full dry days since (plus a trace 0.3mm on May 4th), internal moisture is likely still elevated despite surface drying.
Moderate NE winds (16–20 km/h) and improving humidity (dropping from 84% to 68% today) have aided evaporation on exposed south- and west-facing surfaces, but the relatively cool temperatures (~10°C average) limit drying rate — south-facing formations are the most promising.
With ~28mm absorbed just three days ago and average temperatures only around 10°C, internal moisture levels likely remain above the critical threshold where significant strength loss occurs, posing hold breakage risk particularly on north-facing or shaded features.
Early May conditions are improving but spring at 290m altitude still brings cool nights (near freezing on May 5th–6th), slowing overnight drying and marginally raising freeze-thaw concern for saturated rock.
Contributing Factors
7
27.7mm fell on May 3rd — a substantial soaking event requiring 48–72+ hours of good drying conditions for porous gritstone.
May 5th and 6th have been dry, providing roughly 48 hours of drying time since the last significant rain.
Brimham's open moorland exposure to 15–20 km/h winds significantly accelerates surface evaporation compared to sheltered crags.
Average temperatures around 9–10°C and overnight lows near freezing slow the drying process considerably.
South- and west-facing formations will have dried much faster than north-facing ones, creating highly variable conditions across the site.
Average humidity of 76% over the past week limits evaporation efficiency, though today's daytime drop to ~53% is encouraging.
Light rain forecast for May 7th–8th followed by heavier rain on May 9th–10th will reset drying progress.
Recommendations
3
- If climbing today, focus exclusively on south- and west-facing exposed formations that receive full wind; physically touch the rock and check the ground at the base is bone dry before climbing.
- Avoid north-facing features, low-lying slabs, and any rock near seepage lines or mossy patches — these will still be holding significant moisture internally.
- Given rain returning from tomorrow, today offers the best window this week; if rock feels cold and clammy to the touch, walk away and return after a longer dry spell.
Do Not Climb
45%
3 days ago
Heavy rain on May 3rd (27.7mm) saturated the gritstone only two days ago, and despite today being the second dry day with moderate wind, the rock has not had sufficient drying time — particularly on north-facing formations and lower sections. We recommend waiting at least another day or two before climbing.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Brimham's scattered formations face all compass directions, meaning north- and east-facing sides of towers will have dried significantly slower than south/south-west faces after the May 3rd deluge.
- The complex shapes of Brimham's balanced boulders and pinnacles create sheltered recesses, undercuts, and crevices that trap moisture far longer than the exposed upper surfaces suggest.
- The open moorland position and today's 25 km/h northerly wind are actively assisting drying on exposed south-facing rock, but wind-shadowed faces on the lee side of formations will benefit much less.
- The ground at Brimham is peaty moorland which retains water — if the peat around the base of formations is still damp, the rock almost certainly still holds internal moisture.
Warnings
2
- 27.7mm of rain fell only two days ago — surfaces may appear dry while the interior remains saturated, creating the most dangerous scenario for hold breakage on gritstone.
- Climbing on insufficiently dried Millstone Grit causes permanent, irreversible damage to holds and route quality at this irreplaceable National Trust site.
Reasoning
The 27.7mm deluge on May 3rd would have deeply saturated the porous Millstone Grit, and with only ~1.5 dry days elapsed (plus a trace 0.3mm on May 4th), internal moisture levels are almost certainly still elevated despite surfaces potentially appearing dry.
Today's northerly wind (~25 km/h) and moderate humidity (~72%) are helping, but temperatures have been cool (averaging under 10°C) and the 48-hour window since heavy rain is the absolute minimum drying time — and that assumes ideal conditions, which these are not.
With 27.7mm of rain only two days ago, the rock is likely still above the critical moisture threshold where significant compressive strength loss occurs, posing real risk of hold breakage on gritstone.
Early May temperatures are still cool (overnight lows near freezing on some recent nights), which slows evaporation; the overnight low of -3.1°C on April 24th and -1.4°C on April 14th indicate freeze-thaw risk has only recently diminished.
Contributing Factors
7
27.7mm fell on May 3rd — a significant soaking event requiring 48–72+ hours of good drying conditions before porous gritstone is safe to climb.
Only approximately 1.5 truly dry days have passed since the heavy rain, falling short of the minimum 48–72 hour guideline for heavy rain on porous rock.
Average temperatures since the rain have been around 10°C with overnight lows near 4–6°C, which significantly slows evaporative drying compared to summer warmth.
Brimham's exposed moorland position with 25 km/h northerly winds today is the strongest drying factor, moving moist air from rock surfaces and accelerating evaporation on windward faces.
The 0.3mm on May 4th, combined with 83% humidity and 100% cloud overnight, would have slowed the initial drying phase after the major rain event.
Nearly 50mm of rain in the past 28 days means the rock has been repeatedly wetted through April, keeping background moisture levels elevated even before the May 3rd event.
Today's humidity averaging around 72% is neither ideal nor terrible for drying — it allows some evaporation but is not as effective as the drier 62% forecast for tomorrow.
Recommendations
3
- Wait until at least May 7th (three full dry days after the heavy rain) before climbing, especially if targeting north-facing or sheltered formations.
- If visiting sooner, check the peat and ground at the base of formations — if it's still damp, the rock interior almost certainly is too.
- Prioritise south- and west-facing, wind-exposed upper sections of formations if you must assess conditions, and avoid lower slabs and north-facing cracks entirely.
Do Not Climb
92%
4 days ago
Brimham Rocks received nearly 28mm of heavy rain yesterday (May 3rd) in near-saturated conditions, and the rock will be thoroughly soaked. Even with improving conditions through today, the gritstone needs a minimum of 48–72 hours of dry weather to begin approaching safe climbing conditions after this level of saturation.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Brimham's scattered formations mean north-facing sides of towers and pinnacles will retain moisture far longer than south-facing aspects, and sheltered alcoves between formations can trap damp air.
- The open moorland setting means the peaty ground acts as a moisture reservoir — if the ground around the base of formations is wet or boggy, the rock is certainly still saturated internally.
- Many popular problems at Brimham involve low-level slabs and cracks that collect drainage from above, and these will be the last sections to dry after heavy rain.
- National Trust site with high visitor traffic — climbing on wet gritstone causes permanent erosion damage to these iconic and irreplaceable natural formations.
Warnings
2
- Climbing on saturated gritstone today risks permanent hold breakage and route damage — the rock has lost significant structural strength.
- A frost is forecast for the night of May 6th/7th (min -1.2°C); if the rock still holds internal moisture, freeze-thaw damage could occur.
Reasoning
The 27.7mm of rain on May 3rd fell over many hours (essentially all day) in near-100% humidity, thoroughly saturating the porous gritstone to depth; today's 0.3mm of additional drizzle and overnight 100% humidity have prevented any meaningful drying.
Drying has been negligible — overnight humidity was 97–100% and winds were light (8–15 km/h); although conditions improve through this afternoon with humidity dropping to ~58% by evening, this represents only a few hours of modest surface drying after extreme saturation.
With the rock at or near full saturation from yesterday's prolonged heavy rain, compressive strength is reduced by an estimated 30–50%, making hold breakage and grain loosening a serious and immediate risk.
Spring conditions at 290m altitude with temperatures around 6–14°C provide only moderate drying potential; the forecast shows a possible overnight frost on May 7th (min -1.2°C) which could cause freeze-thaw damage if the rock still holds internal moisture.
Contributing Factors
7
27.7mm of sustained rainfall on May 3rd over 12+ hours in near-saturated atmospheric conditions will have thoroughly wetted the gritstone to considerable depth.
Only ~12 hours have elapsed since the rain largely stopped, with overnight humidity at 97–100%, meaning essentially zero net evaporation has occurred.
The two weeks before May 3rd saw multiple light rain events (April 20, 27, 28, May 2) totalling additional moisture that would have kept the rock from fully drying before yesterday's deluge.
Humidity drops to 58–67% this afternoon with light winds and temperatures reaching ~14°C, which will begin surface drying but is insufficient to dry the interior.
Brimham's exposed position normally aids drying significantly, but today's winds are light (5–13 km/h) and won't provide the strong drying effect the site can benefit from.
Temperatures of 6–14°C today provide some evaporative potential but are not warm enough to drive rapid drying of deeply saturated rock.
Millstone Grit absorbs water readily via capillary action and loses 30–50% of its compressive strength when wet, with significant weakening at only ~1% saturation.
Recommendations
3
- Do not climb today — the rock is thoroughly saturated from yesterday's 28mm of sustained rain and needs a minimum of 48–72 hours of good drying conditions.
- Check conditions from Wednesday May 6th onwards, but only if the forecast remains dry; look for dry ground at the base of formations as a reliable indicator of internal drying.
- If visiting today, enjoy the spectacular landscape and formations — Brimham is a wonderful place for a walk even when the climbing is off-limits.
Do Not Climb
95%
4 days ago
Brimham Rocks received 27.1mm of heavy rain today with 96% humidity, thoroughly saturating the gritstone. The rock will be dangerously weakened internally and needs a minimum of 48–72 hours of dry weather before climbing can be considered.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Brimham's scattered formations mean north-facing sides of towers and pinnacles will retain moisture significantly longer than south-facing aspects after today's heavy soaking.
- The open moorland setting provides excellent wind exposure for drying, but today's NE wind at only 23 km/h combined with near-saturated air (96% humidity) means negligible drying will occur today.
- Many of Brimham's popular problems and routes are on rounded, low-angle features (slabs, mantels) where water pools in horizontal breaks and crystalline hollows, prolonging saturation in critical holds.
- The peat moorland base around the formations acts as a moisture reservoir — if the ground is still boggy at the base of the rocks, internal saturation is virtually guaranteed.
Warnings
2
- 27.1mm of rain today has fully saturated the gritstone — climbing now risks permanent hold breakage and route damage.
- The surface may appear to dry before the interior does; do not be deceived by a dry-looking surface over the next 1–2 days.
Reasoning
With 27.1mm of rain today at 96% humidity, the gritstone will be at or near full saturation (~87–90%), meaning compressive strength is reduced by 10–50% and holds are at serious risk of breakage.
Zero effective drying has occurred today given the near-saturated atmosphere; the rock needs at least 48–72 hours of dry, breezy conditions with lower humidity to approach safe internal moisture levels after this volume of rain.
At near-full saturation, grain cohesion is severely compromised and the risk of hold breakage and permanent surface damage is very high — climbing today would risk irreversible damage to routes.
Spring conditions in late April/early May at 290m altitude mean moderate temperatures (~10°C) that support only slow drying, and the preceding weeks have been intermittently wet (51.9mm in 28 days), meaning the rock has had limited opportunity to fully dry out even before today's deluge.
Contributing Factors
6
27.1mm of rain today is a significant soaking event that will have fully saturated the porous gritstone through its entire depth.
96% humidity means essentially no evaporative drying is occurring — the rock will remain at peak saturation.
51.9mm over the last 28 days with frequent light rain events means the rock had limited baseline drying before today's heavy rain.
The exposed moorland position will aid drying once humidity drops, but today's 23 km/h NE wind into saturated air provides no meaningful benefit.
Temperatures around 10°C are only moderate for evaporative drying and will slow the recovery from full saturation.
With rain falling today, there are zero consecutive dry days — the minimum guideline of 48–72 hours after heavy rain has not even begun.
Recommendations
3
- Do not climb today — the rock is fully saturated and at maximum risk of hold breakage and permanent damage.
- Wait at least 48–72 hours of dry weather before considering a visit; check that the forecast remains dry from tomorrow onwards.
- On return, test conditions by checking the ground at the base of formations — if the peat and soil are still damp, the rock interior is almost certainly still wet.
Do Not Climb
95%
4 days ago
Brimham Rocks received 25.2mm of heavy rain today with 96% humidity — the rock is thoroughly saturated and entirely unsuitable for climbing. Even with exposed moorland winds, gritstone needs a minimum of 48–72 hours of dry weather after this volume of rain before conditions can be considered.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Brimham's scattered formations mean north-facing sides of towers and sheltered alcoves between pinnacles will retain moisture far longer than the exposed south-facing faces, so even as conditions improve, drying will be very uneven across the venue.
- The open moorland position and 290m altitude mean the site benefits from excellent wind exposure for drying, but today's NE wind direction at moderate speed (22.7 km/h) combined with near-saturation humidity (96%) provides virtually no drying benefit.
- Many of Brimham's classic problems are on low boulders and the bases of formations where water pools and drains to — these sections will be the last to dry and should be treated with extra caution even after upper faces appear dry.
- The preceding weeks have been intermittently wet (50mm in 28 days) meaning the rock has had limited opportunity to fully dry out internally before today's heavy soaking.
Warnings
2
- 25.2mm of rain today has fully saturated the gritstone — climbing now risks irreversible hold breakage and route damage.
- Surface-dry appearance can be deceptive on gritstone; significant internal moisture and strength loss persists long after the surface appears dry.
Reasoning
With 25.2mm of rain today at 96% humidity, the gritstone is at or near full saturation — internal moisture levels will be very high across all aspects and elevations.
Drying has not begun in any meaningful sense; today's near-saturated atmosphere and NE wind provide no net evaporation, and the preceding period included frequent light rain events preventing full drying between wettings.
At current saturation levels, gritstone holds are at severe risk of breakage — compressive strength is reduced by 30%+ and grain cohesion is critically compromised, making climbing both dangerous and destructive.
Early May temperatures are moderate (~10°C) which provides only slow drying, and overnight lows near 3–7°C further slow the process; freeze-thaw risk is low but not the concern today — sheer saturation is.
Contributing Factors
6
25.2mm of rain today is a substantial soaking event — well above the 10mm threshold that demands 48–72+ hours of dry weather before climbing.
96% humidity means effectively zero net evaporation from the rock surface, so drying cannot begin until humidity drops significantly.
50mm of rain over the past 28 days with frequent small events means the rock has had limited opportunity to dry out internally before today's heavy soaking.
Brimham's exposed position will aid drying once humidity drops and wind picks up, potentially allowing faster recovery than a sheltered woodland crag.
Wind at 22.7 km/h is moderate, but its drying benefit is entirely negated by today's 96% humidity.
The forecast shows essentially dry conditions from May 4 onwards with declining humidity, which will support progressive drying over the coming days.
Recommendations
3
- Do not climb today — the rock is thoroughly saturated and climbing would risk permanent hold damage and personal injury.
- Wait at least 48 hours (until May 5 at the earliest) and then visually assess conditions on arrival, paying particular attention to north-facing faces and lower sections.
- Check the ground at the base of formations before climbing — if the soil or peat is still damp, the rock interior is almost certainly still wet.
Do Not Climb
95%
4 days ago
Brimham Rocks received 25.4mm of heavy rain today with 96% humidity — the rock is thoroughly saturated and climbing would risk both hold breakage and permanent crag damage. The preceding fortnight also brought frequent light rain events, meaning the rock had limited opportunity to fully dry before today's deluge.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Brimham's diverse formations mean north-facing towers and sheltered alcoves between pinnacles will retain moisture far longer than the exposed south-facing faces, so conditions will vary dramatically across the site.
- The moorland setting means water drains down through the peat and across exposed rock bases — lower sections of boulders and the bases of towers will be the last areas to dry.
- National Trust ownership and high visitor numbers make ethical climbing here especially important; damage to this iconic landscape would threaten continued climbing access.
- Despite the exposed, windy moorland position that normally aids drying, today's NE wind at 96% humidity provides essentially zero drying benefit.
Warnings
3
- 25.4mm of rain today has fully saturated the gritstone — climbing now risks catastrophic hold breakage and irreversible route damage.
- Surface-dry appearance can be deceptive within the next 48 hours; internal saturation will persist even if the surface looks dry.
- North-facing and sheltered formations will remain dangerously wet for several days longer than exposed south-facing rock.
Reasoning
With 25.4mm of rain today at 96% humidity, the gritstone is fully saturated throughout — well above the critical ~1% saturation threshold at which significant weakening begins.
Drying has not meaningfully begun; the NE wind at 22 km/h into near-saturated air (96% RH) provides negligible evaporative potential, and the preceding week's scattered rain events (0.7mm on April 27–28, 0.7mm on May 2) mean the rock never fully dried before today's soaking.
At full saturation, Millstone Grit can lose 30–50% of its compressive strength, making holds prone to breakage — climbing today would risk permanent, irreversible damage to routes.
Early May temperatures around 10°C are moderate but not warm enough for rapid drying; the recent overnight low of 2.4°C on May 1 and forecasted lows near 3–6°C slow internal moisture release.
Contributing Factors
6
25.4mm of rain today is a significant soaking event, thoroughly saturating the porous Millstone Grit throughout.
96% relative humidity means virtually no evaporative drying is occurring, leaving the rock in its fully saturated state.
Multiple small rain events over the past two weeks (50.2mm over 28 days) kept the rock from ever fully drying before today's heavy rain.
The exposed moorland position normally aids drying, but wind into near-saturated air provides negligible benefit today.
Temperatures around 10°C are insufficient to drive rapid evaporation from deeply saturated gritstone.
South-facing formations will eventually dry fastest, but no aspect will be adequately dry given today's heavy saturation.
Recommendations
3
- Do not climb at Brimham today — the rock is thoroughly saturated and climbing risks permanent damage to holds and routes.
- Monitor conditions from May 6 onwards; two full dry days with dropping humidity should allow south-facing exposed formations to begin approaching climbable condition.
- On your first visit back, perform a touch test on the rock and check that the ground at the base of formations is sandy-dry before committing to climb.
Marginal — Assess Conditions
62%
5 days ago
Brimham has had an excellent extended dry spell from April 21–May 1 (10+ days with only trace precipitation), and the rock should be well-dried on most aspects. However, today's 0.2mm trace moisture and tomorrow's forecast for 25mm of heavy rain mean today is the last viable window before a significant wet period — south and west-facing exposed formations should be dry, but on-site verification is recommended given the trace precipitation today.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Brimham's scattered tower and pinnacle formations mean individual boulders dry at very different rates — exposed freestanding towers dry fastest, while sheltered alcoves between formations and north-facing recesses can hold moisture much longer.
- The open moorland setting at 290m provides excellent wind exposure on all aspects, which has been a major drying advantage during the recent dry spell with consistent moderate winds.
- North-facing sides of formations (e.g. Cubic Block north face, Lover's Leap north side) will have received minimal direct sun and should be checked carefully despite the long dry spell.
- The National Trust car park closes at set times and the site can be very busy on dry weekends — arriving early maximises both climbing time and the chance of finding the driest conditions before any afternoon cloud/moisture builds.
Warnings
2
- Tomorrow's forecast of 25mm rain will make the crag unsafe for several days — do not plan climbing for May 3–6.
- Despite the dry spell, always perform the ground-moisture test at the base of formations before climbing: if the ground or moss is damp, the rock interior may still hold moisture.
Reasoning
After 10+ consecutive days with only trace precipitation (0.7mm on Apr 27, 0.2mm on Apr 28, and 0.2mm today), the rock should be substantially dry internally on most aspects, though today's trace moisture and moderate humidity (76%) introduce minor uncertainty.
The extended dry window from April 21 onwards with temperatures reaching 17–20°C and consistent moderate winds (15–25 km/h) on this exposed moorland site would have provided excellent drying conditions, far exceeding the 48–72 hour guideline even for heavier earlier rain.
Structural risk is low today given the prolonged drying period; the gritstone should have regained its full compressive strength on well-drained, sun-exposed faces.
Early May offers improving conditions with longer days and stronger solar angles, though the overnight frost on April 24 (−3.1°C) after a dry period posed no freeze-thaw risk given the low saturation at that point.
Contributing Factors
6
Over 10 days of essentially dry weather (only trace amounts on Apr 27–28) with warm temperatures up to 20.5°C has provided ample drying time well beyond the 48–72 hour guideline.
The 0.2mm recorded today is negligible but breaks the fully dry streak and, combined with 76% humidity, means surfaces may not be bone-dry everywhere.
Consistent moderate winds (15–25 km/h) across the exposed plateau have significantly accelerated evaporation throughout the drying period.
South and west-facing formations will be well-dried, but north and east-facing recesses receive less direct sun and may retain trace dampness in sheltered spots.
A forecast of 25mm rain on May 3 with 91% humidity will thoroughly saturate the rock, making today the last climbing opportunity before an extended wet period.
Early May solar angles and day length are favourable for drying, and overnight temperatures have been above freezing recently, eliminating freeze-thaw concerns.
Recommendations
3
- South and west-facing exposed towers and pinnacles are your best bet today — prioritise these and visually/tactilely check holds before committing to routes.
- Avoid north-facing recesses and any formations surrounded by damp moorland vegetation, which can wick moisture onto rock.
- Climb today if conditions check out on arrival, as the next viable dry window may not arrive until May 8 or later given the incoming wet spell.
Marginal — Assess Conditions
60%
6 days ago
After a largely dry spell from April 21–30 with only trace amounts of rain, conditions had been improving well, but today's 0.5mm of precipitation and the preceding light rain on April 27–28 introduce some uncertainty. South- and west-facing formations are likely dry enough to climb, but north-facing features and lower sections may still hold dampness, and a visual check on arrival is essential.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Brimham's scattered formations face every direction — south-facing towers and slabs will have dried substantially faster than the north-facing walls and shaded gullies between formations, so conditions can vary dramatically within a short walk.
- The open moorland position at 290m means the exposed formations benefit from consistent wind drying, but the numerous sheltered alcoves, chimneys, and crack systems between the towers can trap moisture and remain damp long after exposed faces have dried.
- The National Trust site sees heavy foot traffic and the soft gritstone is already heavily polished in places — climbing on even marginally damp rock accelerates this damage on an irreplaceable landscape.
- Overnight frost on April 24 (min -3.1°C) following the earlier wet period may have caused minor freeze-thaw stress on any rock that still held internal moisture at that point.
Warnings
2
- Heavy rain of 11.6mm is forecast for May 3 — do not climb on May 3 or for at least 48 hours afterwards; the gritstone will be thoroughly saturated.
- Today's 0.5mm of rain means some surfaces may still be damp — do not assume the rock is dry without a physical check.
Reasoning
The last significant rain was 0.5mm today (May 1) and before that only trace amounts on April 27–28 (0.9mm combined), with a genuine dry spell of 5 consecutive dry days from April 21–26; the rock's internal moisture from the heavier mid-April rains (7mm on April 15, 4.3mm on April 11) should have largely dissipated from exposed faces, but today's light rain resets the surface.
The extended dry period from April 21–26 with moderate winds (11–22 km/h) and temperatures reaching 17°C provided good drying conditions for south- and west-facing aspects, but the light rain today (0.5mm) will have re-wetted surfaces that need another 24 hours of dry weather to fully clear.
The cumulative 27mm over the past 28 days with intermittent drying periods means the gritstone has experienced repeated wetting-drying cycles; structural risk is moderate, with exposed faces likely sound but sheltered or north-facing features potentially still holding some internal moisture from the heavier mid-April events.
Early May in Yorkshire is a transitional period with improving temperatures (today reaching 20°C) but still-cool overnight lows near freezing; the April 24 overnight frost of -3.1°C posed freeze-thaw risk to any rock still damp internally, but this risk diminishes as we move into May.
Contributing Factors
7
0.5mm of rain today resets the surface drying clock on exposed faces, requiring at least 24 hours of dry weather to clear.
Five consecutive dry days (April 21–26) with moderate temperatures up to 17°C allowed significant internal drying of the rock from earlier April rainfall.
Brimham's open moorland position has provided consistent wind exposure (averaging ~20 km/h recently) that significantly accelerates evaporation from the gritstone surface.
27mm over 28 days with multiple wetting events means the rock has been repeatedly saturated; sheltered and north-facing features may retain deeper moisture despite surface-dry appearance.
Today's high of 20°C is the warmest this spring, boosting evaporation rates and aiding surface drying throughout the day.
Current humidity of 70% is neither ideal nor prohibitive for drying — evaporation proceeds but not at peak efficiency.
11.6mm of rain forecast for May 3 will thoroughly re-saturate the rock, closing the current drying window and requiring several days of subsequent drying.
Recommendations
3
- If climbing today, focus on south- and west-facing exposed formations that catch the most wind and sun, and perform a tactile check — press your palm to the rock for 10 seconds and check for any dampness.
- Tomorrow (May 2) is forecast dry with moderate temperatures and will be the best day this week; the heavy rain on May 3 will close the window for several days.
- Avoid sheltered chimneys, north-facing walls, crack interiors, and lower sections of formations where moisture lingers longest, even if exposed faces appear dry.
Marginal — Assess Conditions
68%
9 days ago
The rock has had roughly 1.5 dry days since the last trace precipitation (0.2mm on April 28) and nearly a week since any meaningful rain (0.7mm on April 27), with good wind exposure and moderate temperatures aiding drying. South- and west-facing formations should be in reasonable condition, but north-facing aspects and sheltered alcoves may still hold residual moisture from the cumulative wet April, so on-site assessment is essential.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Brimham's scattered tower and pinnacle formations mean each feature has its own microclimate — south-facing faces of prominent towers will have dried significantly faster than recessed north-facing walls tucked between formations.
- The exposed moorland position at 290m provides excellent wind-assisted drying, and the consistent 15–27 km/h winds over the past two days will have helped clear surface moisture effectively.
- Several popular lower-level problems and routes at Brimham sit close to the peaty moorland ground, which retains moisture and can wick dampness into the rock base — check the ground conditions at the base of boulders as a moisture indicator.
- April 2026 has been a persistently damp month with 27.6mm cumulative precipitation spread across many small events, meaning the rock has rarely had extended dry spells to fully purge internal moisture.
Warnings
2
- High overnight humidity (90%+) means early-morning rock surfaces will likely be damp with condensation — wait until mid-morning or later for surfaces to dry.
- The cumulative effect of a wet April means internal moisture may persist even where surfaces appear dry; exercise particular caution on porous, horizontal surfaces and cracks.
Reasoning
The last significant rain was 0.7mm on April 27 followed by 0.2mm trace on April 28, giving roughly 1–2 dry days, but the cumulative 27.6mm across April means the rock's internal moisture levels are likely elevated despite surface drying.
Exposed position with steady NE winds of 21–27 km/h and temperatures reaching 10–14°C over the past two days provide decent drying conditions, though overnight humidity consistently exceeding 90% partially offsets daytime drying progress.
The repeated wetting–drying cycles throughout April combined with several near-zero overnight temperatures create moderate concern for grain loosening, particularly on well-trafficked edges and fragile holds.
Mid-spring conditions are improving with longer days and stronger solar angles, but the persistent dampness of April 2026 and overnight temperatures still dropping near or below freezing (–3.1°C on April 24, –1.4°C on April 14) mean the rock has endured continued stress this season.
Contributing Factors
7
Only 0.9mm in the last 7 days, spread as trace amounts, with the last meaningful event being just 0.7mm on April 27 — well below the threshold for deep saturation.
27.6mm across 28 days with very few extended dry windows means the rock has been repeatedly wetted without full drying, keeping internal moisture levels elevated.
Brimham's exposed moorland position combined with consistent 14–27 km/h winds over the past two days significantly accelerates surface and near-surface drying.
Overnight humidity has consistently exceeded 90% (reaching 94% this morning), depositing condensation on rock surfaces and partially reversing daytime drying gains.
South- and west-facing formations receive good solar heating and will be substantially drier than north- and east-facing surfaces, creating highly variable conditions across the site.
Today's forecast high of 13.9°C with improving late-April solar angle provides reasonable evaporative potential, especially on sun-exposed faces.
The overnight low of –3.1°C on April 24, just days ago, following weeks of repeated wetting means some freeze-thaw damage may have occurred during this cycle.
Recommendations
3
- Focus on south- and west-facing formations that receive direct sun and wind; avoid north-facing walls, shaded recesses, and low boulders near damp peat.
- Perform a tactile and visual check on arrival — if the ground at the base of a boulder feels damp or peaty-wet, the rock above is likely still holding internal moisture.
- Avoid fragile or sandy-textured holds and well-worn edges, as the repeated wetting cycles of April may have loosened surface grains.
Climbing Outlook