Condition Analysis
AI-powered assessment using site data and 14-day weather history
Gabbro at Porth Ysgo is non-porous and dries very quickly, so the light scattered showers of recent days (2.2mm on May 2, 2.1mm on May 3, 0.4mm today including 0.3mm forecast at 15:00) are not a major concern structurally. However, high ambient humidity (~80%), overcast skies, and the light shower expected mid-afternoon today mean surfaces should be visually checked before committing — a dry window exists from late morning through early afternoon and again from late afternoon onward.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Porth Ysgo is semi-tidal: some of the best boulders are only accessible around low tide, so check tide times before making the walk in.
- The gabbro's exceptionally rough texture shreds skin rapidly — tape up early and keep sessions short, especially in humid conditions when skin softens faster.
- Sea spray and salt humidity from the SW-facing coastal aspect can leave a thin moisture film on rock faces even during nominally dry periods, reducing friction despite the rock being non-porous.
- The steep walk down to the beach is slippery when wet — recent light rain and high humidity mean the approach path may be greasy.
Warnings
2
- Be aware that the approach path down to the beach can be slippery in damp conditions — take care on the descent.
- Do not attempt tidal-zone boulders without confirming the tide window; incoming tides can cut off retreat quickly.
Reasoning
The rock surface is likely mostly dry given two consecutive dry days (May 4–6) and only trace/light precipitation since, but today's 0.1mm early morning drizzle and forecast 0.3mm shower at 15:00 may leave brief surface dampness.
Gabbro's zero porosity combined with the exposed, SW-facing aspect and moderate winds (15–20 km/h) means any surface water from light showers will evaporate within 30–60 minutes, though persistent high humidity (~80%) slows final drying.
No structural risk — gabbro is non-porous and extremely hard; water does not penetrate or weaken the rock.
Early May on the Lleyn Peninsula brings lengthening days and reasonable solar angles for the SW aspect, but Atlantic weather systems keep humidity elevated and showers frequent.
Contributing Factors
6
Gabbro does not absorb water and cannot be structurally damaged by moisture, so the primary concern is surface friction rather than rock integrity.
Light rain on May 2–3 (total 4.3mm), trace on May 5, and 0.4mm today mean the surface has been intermittently dampened despite several mostly dry days.
Humidity has averaged around 80–84% over the past week, which can sustain a thin moisture film on rock surfaces and slow evaporation of any dampness.
Moderate winds of 14–20 km/h today aid rapid surface drying on the exposed coastal boulders.
A 0.3mm shower is forecast around 15:00 today, which will briefly wet surfaces and interrupt climbing.
The SW-facing aspect benefits from afternoon sun when clouds break, boosting surface drying, though today is mostly overcast.
Recommendations
3
- Target the late-morning to early-afternoon window (10:00–14:30) before the forecast 15:00 shower, or return after 16:00 once the rock has re-dried.
- Check tide times before setting out — some of the best problems are only accessible around low water.
- Bring plenty of finger tape and spare pads; the abrasive gabbro will eat skin fast, and landings at Porth Ysgo are notoriously poor.
Previous Analyses
Likely Safe to Climb
88%
2 days ago
Gabbro at Porth Ysgo should be fully dry today — the last meaningful rain (2.1mm) fell on May 3rd, followed by two dry days plus today, with moderate winds aiding evaporation. The non-porous gabbro sheds surface water rapidly, and conditions this afternoon look excellent with dropping humidity and light winds.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Semi-tidal venue: some boulders are only accessible around low tide, so check tide times before making the walk in.
- The SW aspect receives good afternoon sun which will help burn off any residual coastal dampness through the day.
- Gabbro's extreme roughness will shred skin quickly — bring finger tape and consider shorter sessions, especially in the slightly cool spring conditions that may mask skin wear.
- The walk-in to Porth Ysgo is steep and can be slippery after rain; the path should be fine today but take care on the descent.
Reasoning
The last notable precipitation was 2.1mm on May 3rd (three days ago), with only a trace 0.1mm on May 5th; the non-porous gabbro will have shed all surface moisture long ago.
Two full dry days with moderate northerly winds (22–28 km/h) on exposed coastal rock have provided ample drying time — gabbro typically dries within an hour or two of rain stopping.
Gabbro is extremely hard and non-porous, so there is zero risk of structural weakening or hold breakage from moisture.
Early May provides reasonable daylight hours and mild temperatures (12°C); spring conditions are generally favourable though coastal humidity remains moderate.
Contributing Factors
6
No significant rain since May 3rd (2.1mm), with only a trace on May 5th, giving ample time for the non-porous gabbro to dry completely.
Gabbro does not absorb water at all, so surface moisture is the only concern and it evaporates rapidly.
Exposed coastal position with consistent winds (18–28 km/h recent days) accelerates surface drying.
Today's humidity drops to 64–67% through the afternoon, reducing any condensation risk on the rock surface.
SW winds are light today (5–12 km/h) so sea spray is unlikely to be an issue, though lower boulders near the tideline may have residual dampness.
A significant 9.6mm of rain is forecast for May 9th, which will interrupt the current dry spell.
Recommendations
3
- Target the afternoon session (12:00–17:00) when humidity is lowest and any overnight condensation has cleared.
- Check tide times before setting out — some of the best problems are only accessible around low water.
- Bring finger tape and spare skin care; the gabbro is exceptionally abrasive and spring-cool skin wears faster than you'd expect.
Likely Safe to Climb
90%
3 days ago
Porth Ysgo's non-porous gabbro has had two full dry days with moderate northerly winds, and the last rain (2.1mm on May 3rd) was light — the rock will be thoroughly dry. Today's afternoon looks excellent with clearing skies, dropping humidity (into the 60s%), and a steady northerly breeze.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Some lower boulders are semi-tidal and only accessible around low water — check tide times for the Lleyn Peninsula before setting out, as access windows may be limited.
- The gabbro here is notoriously skin-shredding; after a prolonged wet spring period the rock's crystals will feel especially aggressive, so bring tape and plan session length carefully.
- Northerly wind today will blow directly onshore at this SW-facing crag, helping to keep surfaces dry but potentially feeling cold at ~12°C — bring layers.
- Sea spray from Atlantic swell can deposit moisture on lower boulders even on dry days; inspect holds on the lowest problems closest to the waterline before committing.
Warnings
2
- Some boulders are only accessible at low tide — always check tide times and be aware of rising water cutting off retreat.
- Landings at Porth Ysgo are generally poor; bring multiple bouldering pads and a spotter for committing problems.
Reasoning
The last meaningful rain was 2.1mm on May 3rd, followed by two completely dry days; gabbro's zero porosity means any surface moisture will have evaporated within hours of the rain stopping.
Moderate northerly winds (22–28 km/h) over the past two days combined with the SW aspect receiving afternoon sun have provided excellent drying conditions for this non-porous rock.
Gabbro is extremely hard and dense with no porosity — there is zero risk of structural weakening or hold breakage from moisture, and the recent rain totals are modest.
Early May on the Lleyn coast offers reasonable daylight hours and mild temperatures; spring seabird nesting restrictions should be checked but gabbro bouldering at beach level is typically unaffected.
Contributing Factors
6
No rain since 2.1mm on May 3rd, which is more than ample drying time for non-porous gabbro.
Gabbro does not absorb water and dries rapidly, so even light recent rain poses no structural or deep-moisture concern.
Humidity forecast to drop to 59–64% through the afternoon with clearing skies, providing good friction conditions.
Steady 20–23 km/h northerly wind will keep surfaces dry and assist evaporation of any residual dampness.
The exposed coastal setting means Atlantic swell could deposit spray on the lowest boulders, but current wind speeds are moderate and conditions appear manageable.
Some boulders require low tide access — this doesn't affect rock condition but limits which problems are available at any given time.
Recommendations
3
- Target the afternoon session (11:00–18:00) when humidity is lowest and skies are clearest for the best friction.
- Check Lleyn Peninsula tide tables before heading out — plan around low water to maximise access to all boulders.
- Bring finger tape and limit session length; the exceptionally rough gabbro texture will destroy skin quickly, especially in the dry conditions.
Likely Safe to Climb
88%
4 days ago
Gabbro at Porth Ysgo should be dry and in excellent condition today. The last meaningful rain (2.1mm) fell on May 3rd morning, but non-porous gabbro with SW aspect, exposed wind, and a full day of drying will have shed surface moisture quickly; today is completely dry with strengthening northerly winds and declining humidity through the afternoon.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Porth Ysgo is semi-tidal — some of the best boulders sit low and may retain salt spray or seawater dampness even when the rock above the tide line is bone dry; check tide tables and plan around low water.
- The gabbro's exceptionally rough crystalline texture is notoriously skin-destroying — after the recent damp spell the rock may feel even more abrasive than usual, so bring tape and plan a shorter session.
- Northerly wind today blows directly onto the SW-facing boulders from behind/above, which aids evaporation but won't provide the same direct solar warming as a southerly airflow would; afternoon sun will still reach the faces.
- The approach path down to the beach can be muddy and slippery after the recent wet spell — take care on the steep descent even though the rock itself is fine.
Warnings
2
- Approach path and grassy slopes will be slippery after the recent wet spell — take care on the steep descent to the beach.
- Check swell forecasts as well as tide times; Atlantic groundswell can make lower boulders dangerous or inaccessible even on a calm, dry day.
Reasoning
The last rain was light (2.1mm on May 3rd, mostly before 06:00), and non-porous gabbro will have shed all surface water within hours given the moderate winds and daytime temperatures that followed.
Over 24 hours of dry weather with winds of 17–29 km/h and an exposed coastal position means any residual surface moisture from yesterday's light rain has fully evaporated; humidity is dropping through today from 96% overnight to around 69% by late afternoon.
Gabbro is extremely hard, dense, and non-porous — there is zero risk of structural weakening or hold breakage from recent rainfall.
Early May offers reasonable daylight hours and mild temperatures (13–14°C); spring conditions on the Lleyn Peninsula coast are generally favourable, though seabird nesting season is underway and climbers should respect any local restrictions.
Contributing Factors
6
Gabbro does not absorb water at all, so surface moisture from yesterday's 2.1mm of rain will have evaporated rapidly.
No precipitation since early morning May 3rd, giving well over 24 hours of drying time on a rock type that needs only minutes to hours.
Winds of 20–29 km/h at an exposed coastal site accelerate evaporation of any residual surface film.
Humidity drops from overnight highs of 96% to around 69% by late afternoon, reducing condensation risk on rock surfaces.
While 4.5mm fell in the last 7 days and the ground is generally damp, this only affects approach paths and seepage — the non-porous gabbro boulders themselves are unaffected.
Some boulders are only accessible around low tide; climbers must check tide tables independently as this affects which problems are available.
Recommendations
3
- Plan your session for the afternoon when humidity is lowest (sub-75%) and any overnight condensation has fully cleared — the window from 11:00 to 18:00 looks ideal.
- Check tide tables for Aberdaron/Porth Ysgo before setting out, as lower boulders may be inaccessible or wave-washed at higher states of tide.
- Bring finger tape and plan a moderate-length session — the gabbro's abrasive texture will shred skin rapidly, especially early in the season when skin condition is typically less hardened.
Marginal — Assess Conditions
70%
4 days ago
Today has seen 2.1mm of rain with high humidity (87%), but gabbro's non-porous nature means surface moisture will clear quickly in the moderate northerly wind. Conditions are likely climbable later today if rain has stopped, but on-site verification is needed given the damp morning.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Porth Ysgo's gabbro is non-porous and dries exceptionally fast — surface water from today's light rain could clear within an hour or two in the current 21.6 km/h northerly wind.
- The SW-facing aspect means the boulders will receive afternoon sun, which will aid drying through the latter part of the day despite the northerly wind direction.
- Semi-tidal access is critical: some of the best boulders are only reachable around low tide, so climbers must check tide tables before committing to the walk-in.
- The extremely rough gabbro texture will shred skin rapidly, especially in cooler damp conditions when skin is softer — bring tape and plan for shorter sessions.
Warnings
1
- Some boulders near the waterline may have salt spray or residual wave-wash regardless of rain — assess landings carefully as poor landings are a known hazard here.
Reasoning
Today's 2.1mm of rain on non-porous gabbro will sit as surface water only, and with 21.6 km/h northerly wind and moderate temperatures (~14°C), surface drying should be rapid once precipitation ceases.
The exposed coastal position and moderate wind will clear surface moisture within 1–2 hours of rain stopping; the SW aspect will benefit from afternoon sun to accelerate this further.
Gabbro is extremely hard, dense, and non-porous — there is zero risk of structural weakening or hold breakage from moisture, regardless of recent rainfall.
Early May offers reasonable daylight hours and improving temperatures; the preceding extended dry spell (Apr 18–30, 13 consecutive dry days) means no residual ground seepage concerns — only today's fresh rain is relevant.
Contributing Factors
6
2.1mm of rain today means surfaces may still be damp, though this is a modest amount on non-porous rock.
Gabbro does not absorb water at all, so drying is purely a surface process and occurs very quickly.
21.6 km/h wind at this exposed coastal site will strip surface moisture rapidly once rain stops.
87% humidity slows evaporation somewhat, meaning surface films may linger longer than on a dry-air day.
The south-westerly aspect will receive direct afternoon sunshine, boosting drying on the main boulder faces.
Thirteen consecutive dry days (Apr 18–30) before the recent light showers means no lingering ground-level seepage.
Recommendations
3
- Wait until afternoon for the best chance of fully dry surfaces — the combination of afternoon sun on the SW-facing boulders and continued wind should clear any remaining moisture.
- Check tide tables before heading down — some of the best problems are only accessible around low tide, and the walk-in is significant.
- Bring plenty of finger tape; the gabbro is notoriously skin-destructive, and slightly damp conditions will soften skin further, increasing the risk of painful flappers.
Marginal — Assess Conditions
72%
4 days ago
Today saw 2.1mm of rain with high humidity (87%), but gabbro's non-porous nature and the exposed, windy conditions (22.7 km/h northerly) mean surface moisture should clear relatively quickly. A visual check on arrival is warranted before committing to problems, especially on any north-facing or shaded surfaces.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Porth Ysgo's semi-tidal access means some of the best boulders are only reachable around low tide — check tide tables before the walk-in, as the approach is long and remote.
- Salt spray and sea-level humidity can leave a thin moisture film on lower boulders even after the rock itself has dried, reducing friction despite gabbro's excellent texture.
- The extremely rough gabbro texture shreds skin rapidly — after a prolonged wet spell like mid-April, any residual dampness amplifies abrasion, so tape up early and manage session length.
- Landings at Porth Ysgo are notoriously poor with uneven rocky ground; damp conditions increase slip risk on approach scrambles and landing zones — bring multiple pads and a spotter.
Warnings
2
- Semi-tidal boulders can become inaccessible or dangerous if the tide turns during your session — always know the tide schedule and leave a safety margin.
- Poor landings on uneven rocky ground are more hazardous when damp; take extra care with pad placement and use a spotter.
Reasoning
Today's 2.1mm of rain on non-porous gabbro with 87% humidity means surfaces are currently wet or damp, though the rock itself cannot absorb water.
The 22.7 km/h northerly wind on an exposed coastal site will strip surface moisture efficiently, but the SW-facing aspect receives limited direct benefit from a north wind and afternoon sun may be partially obscured by cloud cover given the high humidity.
Gabbro is extremely hard and non-porous — there is zero risk of structural weakening or hold breakage from moisture, regardless of recent rainfall.
Early May in North Wales offers reasonable daylight hours and moderate temperatures (~14°C), but the recent unsettled spell with frequent rain (4.5mm in the last week) keeps ambient humidity elevated, slowing the final stages of surface drying.
Contributing Factors
6
2.1mm of precipitation today means surfaces were wet earlier; with 87% humidity, evaporation is slower than ideal.
Gabbro cannot absorb water and dries from the surface only, meaning drying times are measured in hours rather than days.
22.7 km/h northerly wind at an exposed coastal location actively strips surface moisture and promotes rapid drying.
Humidity at 87% today (and averaging 74% over the past week) slows the final drying of thin moisture films and can leave a greasy feel.
Rain fell on May 1st (0.2mm), May 2nd (2.2mm), and today (2.1mm), meaning the site has had no sustained dry spell to fully air out.
The exceptionally coarse crystal structure of gabbro provides usable friction even when marginally damp, unlike smoother rock types.
Recommendations
3
- Visit later in the day to allow maximum drying time from this morning's rain — afternoon sessions will find drier rock, especially on sun-exposed SW faces.
- Physically touch-test boulders before climbing: gabbro can appear dry while retaining a thin moisture film from salt spray or residual humidity.
- Check tide times carefully before committing to the long walk-in — some of the best problems are only accessible around low water.
Marginal — Assess Conditions
70%
4 days ago
Porth Ysgo received 1.8mm of rain today and light rain on previous days, but the non-porous gabbro at this exposed, low-altitude coastal site dries rapidly. Surface moisture from today's rain should clear quickly in the northerly wind, but high humidity (89%) may slow the process — a visual check on arrival is advisable.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Gabbro's zero porosity means today's 1.8mm rain sits on the surface only and will shed quickly, but the exceptionally rough texture can trap small pools in micro-features and crystal pockets that take longer to evaporate in high humidity.
- The site is semi-tidal — some of the best boulders are only accessible at low tide, so climbers must check tide times for the Lleyn Peninsula coast before committing to the walk-in.
- The SW-facing aspect will receive good afternoon sun today if skies clear, which combined with the moderate northerly wind (22.7 km/h) should promote rapid surface drying by mid-afternoon.
- Sea spray and coastal mist can re-dampen surfaces independently of rainfall at this exposed beach venue, particularly with onshore winds — today's northerly wind is offshore, which is favourable.
Warnings
2
- Some boulders may have residual sea spray or tidal dampness independent of rainfall — test friction carefully on lower problems near the waterline.
- Landings at Porth Ysgo are generally poor; bring multiple pads and a spotter, especially as damp rock increases the chance of unexpected slips.
Reasoning
Today's 1.8mm rain on non-porous gabbro will produce only surface moisture with no absorption, but 89% humidity and recent dampness from 2.2mm yesterday means surfaces may still be wet or greasy in sheltered spots.
The exposed, SW-facing coastal position at just 10m altitude combined with a 22.7 km/h northerly wind will promote rapid surface drying, and gabbro typically dries within hours of rain ceasing — conditions should improve significantly through the afternoon.
Gabbro is extremely hard and dense with zero porosity, so there is no risk of structural weakening, hold breakage, or rock damage from climbing on damp rock.
Early May in North Wales offers reasonable daylight hours and moderate temperatures (13.5°C max today), though the recent unsettled spell with elevated humidity is typical of spring on the Lleyn Peninsula.
Contributing Factors
7
1.8mm of precipitation today means surfaces will be wet, though the non-porous gabbro sheds water rapidly once rain stops.
Humidity at 89% today and averaging 75% over the past week will slow evaporation of surface moisture and may leave a greasy film on holds.
Gabbro does not absorb water at all, so drying is purely a surface phenomenon and occurs much faster than on any porous rock type.
A 22.7 km/h northerly wind at this fully exposed coastal site will actively strip surface moisture from the rock.
The south-westerly aspect will catch afternoon sun if skies clear, warming rock surfaces and accelerating drying.
The exceptionally coarse crystal texture of Lleyn gabbro provides significantly better friction in marginal dampness than most other rock types.
After a prolonged dry spell from April 18–30, light rain has returned over the last three days (total ~4.2mm), but amounts are modest and the gabbro won't retain any of it.
Recommendations
3
- Wait until mid-to-late afternoon to allow today's rain to dry off — inspect holds by touch before committing to problems, particularly in north-facing or sheltered corners.
- Check Lleyn Peninsula tide times before setting out, as several of the best problems are only accessible at low tide and the walk-in is substantial.
- Bring plenty of finger tape — the abrasive gabbro texture will shred skin rapidly, especially in slightly damp conditions where you may grip harder than usual.
Marginal — Assess Conditions
60%
5 days ago
Today has seen 2.2mm of rain with very high humidity (93%), so the gabbro is likely still damp right now. However, given gabbro's non-porous nature and the exposed coastal setting, surfaces could dry quickly if rain has stopped and any breeze picks up — a visual check on arrival is essential.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Porth Ysgo is semi-tidal: some boulders are only accessible at low tide, so check tide times carefully before committing to the approach.
- Sea spray and coastal mist can keep surfaces damp even after rain stops, particularly on lower boulders closer to the waterline.
- The extremely rough gabbro texture shreds skin rapidly — in humid conditions skin stays softer and wears even faster, so bring tape and plan shorter sessions.
- The poor landings and remote beach setting mean a slip on damp rock carries higher consequence; multiple pads and a spotter are strongly recommended.
Warnings
2
- Rock surfaces may appear dry but retain a thin film of moisture in this humidity — test friction carefully on easy terrain before committing to harder problems.
- Poor landings on a remote beach mean any fall from greasy holds carries serious injury risk; bring multiple pads and a spotter.
Reasoning
Today's 2.2mm of rain and 93% humidity mean surfaces are almost certainly damp right now, though the non-porous gabbro will not have absorbed any moisture internally.
The SW-facing aspect and exposed coastal position should promote rapid surface drying once rain ceases, but the light southerly wind (16.9 km/h) and extreme humidity will slow evaporation today.
Gabbro is extremely hard and dense with zero porosity — there is no risk of structural damage or hold breakage from moisture.
Early May provides reasonable daylight hours and moderate temperatures (~13°C), but the recent wet spell with persistent high humidity means conditions are marginal for friction despite the season.
Contributing Factors
6
2.2mm of rain today with 93% humidity means surfaces are likely still wet or damp, significantly reducing friction even on rough gabbro.
Gabbro does not absorb water at all, so drying is purely a surface phenomenon and can occur rapidly once rain stops.
The exposed coastal position allows wind to strip surface moisture quickly, though today's 16.9 km/h southerly is moderate rather than strong.
An exceptional 13-day dry spell from April 18–30 means the surrounding ground and environment are not waterlogged, aiding overall drying.
Humidity has been 81–93% over the last two days, slowing evaporation and potentially leaving a greasy film on holds.
The south-westerly aspect receives good afternoon sun which will help dry surfaces if cloud breaks, though overcast conditions may limit this.
Recommendations
3
- Wait for rain to fully stop and allow at least 1–2 hours of breeze before attempting any problems; test friction on easy rock first.
- Check tide times before setting out — some of the best boulders are only accessible at low tide and the approach is remote.
- Bring plenty of tape for skin protection as the rough gabbro combined with humid conditions will wear fingertips very quickly.
Marginal — Assess Conditions
72%
6 days ago
Today saw 1.2mm of light rain, breaking an excellent 13-day dry spell. Given gabbro's non-porous nature and the site's exposed, SW-facing aspect, surface moisture should clear quickly, but with high humidity (83%) and moderate winds, some dampness may linger in sheltered spots. Conditions are likely fine but warrant a visual check on arrival.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Porth Ysgo is semi-tidal — some of the best boulders are only accessible at low tide, so check tide times before committing to the walk in.
- The gabbro's exceptionally rough texture shreds skin rapidly; after 13 dry days of potential traffic and with good friction likely, bring tape and manage session length carefully.
- Coastal sea spray and salt mist can leave a residual film on holds even without rain, particularly on the lowest boulders closest to the waterline.
- The steep walk down to the beach is itself slippery when wet — today's rain may make the approach path greasy even if the rock itself is dry.
Warnings
2
- The steep approach path down to the beach may be slippery after today's rain — take care on the descent.
- Check BMC RAD for any active bird nesting restrictions before visiting, as spring nesting season is underway.
Reasoning
Today's 1.2mm of light rain on non-porous gabbro will sit on the surface only; with the SW aspect and moderate wind, most surfaces should be dry or nearly dry by mid-afternoon.
Gabbro's zero porosity means surface water evaporates or runs off quickly; the exposed coastal position and 19 km/h SW wind aid drying, though 83% humidity slows the final evaporation stage.
Gabbro is extremely hard and dense — there is zero risk of structural weakening or hold breakage from moisture; the rock is impervious.
Early May is a good window for Porth Ysgo with lengthening days and reasonable temperatures; the preceding 13-day dry spell was exceptional, and the forecast looks very promising from May 3rd onward.
Contributing Factors
6
1.2mm fell today, breaking a long dry spell and leaving potential surface moisture on holds, particularly in sheltered or north-facing nooks.
Gabbro does not absorb water at all, so surface moisture is the only concern and it clears rapidly.
The exposed, wind-swept coastal setting accelerates surface drying significantly.
Humidity at 83% slows evaporation and may keep surfaces feeling damp longer than expected.
13 consecutive dry days (April 18–30) mean there is no residual deep-seated moisture in cracks or seepage lines.
Only 0.2mm forecast tomorrow with dry conditions from May 3rd onward, dropping humidity and northerly winds — conditions will improve rapidly.
Recommendations
3
- Visit later in the day to allow morning moisture to clear, and visually check holds for dampness before committing to problems.
- Check tide times carefully — some boulders are only accessible at low tide, and planning around both tides and drying conditions will maximise your session.
- Bring tape and spare skin care — the gabbro is brutally abrasive, especially with good friction after the dry spell.
Likely Safe to Climb
95%
9 days ago
Porth Ysgo is in excellent condition today — 12 consecutive dry days, low humidity (54%), and strong easterly winds have left the non-porous gabbro thoroughly dry. This is as good as spring conditions get on the Lleyn Peninsula.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Semi-tidal venue: some boulders are only accessible at low tide — check tide tables for Aberdaron before setting out, as the walk-in is remote and timing is critical.
- Easterly winds today provide less direct drying benefit to the SW-facing boulders than the prevailing westerlies, but 12 dry days render this irrelevant for surface moisture.
- The gabbro's exceptionally rough texture will shred skin quickly in these dry, low-humidity conditions — bring tape and plan for shorter sessions than you might expect.
- Coastal sea spray can dampen lower boulders near the waterline even in dry weather; inspect holds on the lowest-lying problems before committing.
Warnings
2
- Landings at Porth Ysgo are generally poor — bring multiple bouldering pads and ideally a spotter, especially on the higher problems.
- Be aware of tidal movements: getting cut off by the tide at this remote beach could be dangerous.
Reasoning
With 12 consecutive dry days and zero precipitation in the last week, the non-porous gabbro surfaces will be completely dry — there is no residual moisture concern whatsoever.
Although gabbro dries within hours due to zero porosity, the extended dry spell with moderate winds and decent temperatures means even sheltered nooks and seepage lines will be bone dry.
Gabbro is extremely hard and dense with no porosity — there is zero risk of structural weakening or hold damage from moisture, and the recent dry spell further eliminates any concern.
Late April offers improving day length and temperatures (17°C today), though spring conditions on the Lleyn coast can change rapidly; the current settled high-pressure pattern is ideal.
Contributing Factors
6
Twelve consecutive dry days with 0.0mm in the last week ensures even the most sheltered surfaces are completely dry.
Current humidity of 54% is unusually low for this coastal site, minimising any condensation or dampness risk.
36 km/h easterly winds at this exposed coastal site keep surfaces dry and free from residual dampness.
A maximum of 17.2°C today promotes evaporation and comfortable climbing conditions on the rough gabbro.
Gabbro does not absorb water, so even if conditions were less ideal the rock would dry rapidly once rain stops.
Semi-tidal access does not affect rock dryness but climbers must plan around tide times to reach certain boulders.
Recommendations
3
- Check tide tables for Aberdaron/Porth Ysgo before heading out — some of the best problems are only accessible at low tide.
- Bring plenty of finger tape and plan for a shorter session than usual; the dry, low-humidity gabbro will be exceptionally abrasive on skin.
- Conditions are excellent today and tomorrow — take advantage of this settled spell before light rain arrives on May 1st.
Climbing Outlook