Condition Analysis
AI-powered assessment using site data and 14-day weather history
Gabbro at Porth Ysgo received rain earlier this morning but the non-porous rock should dry quickly once showers stop; a dry window looks possible from mid-afternoon onward, though humidity remains high and heavy rain is forecast for the coming days. Climbers visiting this afternoon should visually check surfaces and be prepared for reduced friction from residual moisture and salt spray.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The gabbro is non-porous and dries extremely fast — surface water from this morning's showers will clear within an hour or two of dry, breezy conditions, but coastal humidity and salt spray can leave a thin moisture film that reduces friction.
- Semi-tidal access means some of the best boulders may be cut off at high water — check tide times carefully, especially given the unsettled forecast limiting available sessions over the coming days.
- The SW aspect receives afternoon sun when cloud breaks, which aids drying; today's clearing skies from mid-afternoon should help, but 100% cloud cover through the morning will have slowed evaporation.
- Landings on the beach boulders are generally poor — wet sand and seaweed from recent rain and high seas increase the risk of pad slippage on impact.
Warnings
2
- Heavy rain is forecast for the next three days (16.7mm, 10.0mm, 9.9mm) — today's afternoon may be the last reasonable session window until August 31st at the earliest.
- Wet sand, seaweed, and damp landings increase the risk of pad slippage — take extra care with spotting and pad placement.
Reasoning
Rain fell until around 06:00 this morning (approximately 6mm total), and while the non-porous gabbro sheds water rapidly, high humidity (85–96%) through the morning will have slowed surface drying, leaving likely residual dampness until afternoon.
With the SW-facing aspect, moderate easterly wind, and cloud breaking from mid-afternoon, the rock should be surface-dry by around 15:00–16:00; gabbro's zero porosity means no internal moisture retention.
Gabbro is extremely hard and non-porous — there is no risk of structural weakening or hold breakage from moisture, even after repeated wetting.
Late August offers reasonable daylight hours and temperatures around 20°C, but the pattern is turning distinctly autumnal with an unsettled, wet spell forecast for the next several days.
Contributing Factors
6
Gabbro does not absorb water and dries very rapidly, meaning this morning's rain poses no structural risk and surface moisture will clear quickly once conditions allow.
Approximately 6mm of rain fell between 01:00 and 06:00 with humidity peaking at 97%, and residual dampness may linger through the morning under full cloud cover.
Rain stops by mid-morning and cloud begins to break from 15:00, with humidity dropping to ~80% and light winds aiding surface drying through the afternoon.
Persistent coastal humidity around 80–90% and salt spray can leave a thin moisture film on exposed gabbro surfaces, reducing friction despite the rock's inherent roughness.
16.7mm forecast tomorrow, 10.0mm on the 28th, and 9.9mm on the 29th will keep the site repeatedly wet, making today's afternoon potentially the last viable window for several days.
The exposed coastal position with consistent winds around 15–24 km/h helps strip surface moisture from the rock quickly between showers.
Recommendations
3
- If visiting today, wait until mid-afternoon (15:00+) when cloud breaks and surfaces have had several hours to dry; visually and physically check rock surfaces for dampness before committing to problems.
- Check tide times before setting out — semi-tidal access means some boulders will be unavailable around high water, and the limited dry window today makes timing doubly important.
- Bring extra chalk and finger tape; the abrasive gabbro texture combined with any residual moisture will shred skin rapidly, and high humidity reduces chalk effectiveness.
Previous Analyses
Likely Safe to Climb
92%
57 days ago
Porth Ysgo's gabbro is in excellent condition today — three full dry days with an easterly breeze and low humidity have thoroughly dried the non-porous rock after the rain on August 21st. Today is dry throughout with humidity dropping to the low 40s this afternoon, making for superb friction conditions.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Semi-tidal venue: some of the best boulders are only accessible around low tide, so check tide tables before making the long walk in.
- The extremely rough gabbro texture shreds skin rapidly — bring finger tape and plan shorter sessions, especially in warm dry conditions when sweat softens skin further.
- The steep walk down to the beach and remote location mean self-rescue is difficult; bring multiple pads as landings are rocky and uneven.
- Coastal salt spray and sea mist can create a thin moisture film on lower boulders even on otherwise dry days — wipe holds before committing to a problem.
Warnings
2
- Landings at Porth Ysgo are poor and rocky — bring multiple bouldering pads and a spotter.
- The venue is remote with no mobile signal in places; self-rescue may be necessary.
Reasoning
Three consecutive dry days following the 8.1mm rain on August 21st, combined with today's low humidity (dropping to 40%) and an exposed easterly wind, mean the non-porous gabbro surface will be completely dry.
Gabbro's zero porosity and the site's exposed, SW-facing coastal position with steady 24 km/h easterly winds mean surface moisture would have evaporated within hours of the last rain — three dry days is more than sufficient.
Gabbro is extremely hard and non-porous, so there is no structural weakening risk from recent moisture; holds are stable.
Mid-to-late summer provides long daylight hours and reasonable temperatures, giving an extended climbing window; skin condition is the main limiting factor on warm days.
Contributing Factors
6
No meaningful precipitation since 8.1mm on August 21st, providing ample drying time for non-porous gabbro.
Humidity drops to 40–48% through the afternoon, well below coastal norms and excellent for friction.
Steady 24 km/h easterly wind accelerates surface drying and keeps sea spray off the SW-facing rock.
Gabbro does not absorb water and dries extremely quickly, so even recent light showers pose no structural concern.
Highs around 22°C with sunshine aid rapid evaporation and provide comfortable climbing conditions.
The easterly wind direction today pushes spray away from the cliff face, minimising any salt moisture film.
Recommendations
3
- Head out this afternoon when humidity is at its lowest (40–50%) for the best friction and driest holds.
- Check tide times before the walk in — some boulders are only accessible around low water.
- Bring finger tape and plan for a shorter session; the abrasive gabbro will wear skin quickly in these warm, dry conditions.
Likely Safe to Climb
88%
58 days ago
Porth Ysgo's non-porous gabbro has had two full dry days with moderate northerly winds following the rain on Aug 20–21, and today is dry — the rock should be thoroughly dry and ready to climb. Tomorrow (Aug 24) looks excellent with warm, dry easterly winds and low humidity, but significant rain arrives from Aug 25 onward.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Semi-tidal venue: some of the best boulders are only accessible around low tide, so check tide tables before committing to the walk-in.
- The SW-facing aspect has received limited direct solar benefit from the recent northerly winds, but the exposed position and non-porous rock type compensate well.
- Gabbro's extreme roughness will shred skin quickly — tape up early and consider shorter sessions, especially in humid coastal conditions where sweat compounds the abrasion.
- The approach involves a steep descent to the beach; after recent rain the path may be slippery even if the rock itself is dry.
Warnings
2
- Significant rain (10.9mm+) is forecast from Aug 25 onwards — while gabbro dries quickly, persistent rain through Aug 25–28 will keep surfaces wet and landings poor.
- Groundswell from southwesterly winds on Aug 28 (40 km/h SW) could make tidal boulders inaccessible or dangerous regardless of rock dryness.
Reasoning
The last significant rain was 8.1mm on Aug 21, followed by two completely dry days with moderate wind — non-porous gabbro will have shed all surface moisture well within this window.
Two dry days with 20–24 km/h northerly winds at an exposed coastal site are more than sufficient to dry non-porous gabbro, which typically dries within hours of rain stopping.
Gabbro is one of the hardest, most durable rock types in the UK and faces zero structural risk from moisture — no porosity means no freeze-thaw or saturation concerns.
Mid-to-late summer provides reasonable daylight hours and temperatures; humidity has been elevated (83% average over 7 days) but this causes no structural concern for gabbro and only marginal friction reduction on such a rough-textured rock.
Contributing Factors
6
Gabbro does not absorb water and dries extremely quickly, making two dry days more than adequate drying time.
No precipitation since Aug 21 (8.1mm), with today also dry, giving ample time for all surface moisture to evaporate.
Consistent 19–24 km/h winds over the past two days at this exposed coastal site accelerate surface drying.
Humidity averaging 83% over the past week may leave a faint moisture film, but gabbro's extreme roughness still provides excellent friction.
Some boulders are only accessible at low tide, requiring advance planning regardless of rock conditions.
Nearly 39mm of rain is forecast over the next six days starting Aug 25, so the current dry window is narrow.
Recommendations
3
- Climb today or tomorrow (Aug 24) to take advantage of this dry window before significant rain arrives from Aug 25.
- Check tide tables carefully — plan your session around low water to access all the boulders.
- Bring plenty of finger tape and expect rapid skin wear; consider shorter sessions and allow rest days between visits.
Marginal — Assess Conditions
72%
59 days ago
Yesterday's 8.1mm rain is the main concern, but non-porous gabbro at an exposed, SW-facing coastal site dries rapidly — today's dry weather with moderate northerly winds should have cleared surface moisture by now. However, high recent humidity (84% average) and salt spray from yesterday's conditions may leave residual dampness in sheltered spots, so a visual check on arrival is warranted.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Yesterday's 8.1mm (Aug 21) followed 5.6mm on Aug 20 — a wet couple of days, but gabbro's zero porosity means only surface water needs to evaporate, which happens quickly in wind.
- Northerly winds today and tomorrow don't directly hit the SW-facing boulders, reducing drying efficiency compared to a southwesterly breeze — sheltered nooks may retain dampness longer.
- Semi-tidal access means some lower boulders may have been wave-washed regardless of rain; check tide times and be aware that groundswell from recent weather could limit access to sea-level problems.
- The exceptionally rough gabbro texture retains good friction even when slightly damp, but coastal humidity and salt film can create a deceptive slippery sheen on otherwise dry-looking rock.
Warnings
1
- Recent swell from the wet, windy period (Aug 20–21) may affect access to tidal boulders even if weather is now calm — assess sea conditions on arrival.
Reasoning
The 8.1mm rain yesterday on non-porous gabbro will have sat as surface water only; with today's dry conditions, moderate wind (21 km/h N), and 78% humidity, the majority of surfaces should be dry but sheltered or north-facing features may retain dampness.
One full dry day with moderate northerly wind at an exposed coastal site is generally sufficient for non-porous gabbro, though the SW aspect receives limited direct drying benefit from a northerly wind and humidity remains moderately high at 78%.
Gabbro is extremely hard, dense, and non-porous — there is zero risk of structural weakening or hold breakage from moisture.
Mid-to-late August offers reasonable daylight hours and moderate temperatures; recent humidity has been elevated (84% 7-day average) which is typical of Atlantic-influenced Welsh coastal summer weather.
Contributing Factors
6
8.1mm yesterday and 5.6mm on Aug 20 represent a wet two-day spell, though non-porous gabbro sheds surface water rapidly.
Today has been dry with moderate wind, which is typically sufficient for gabbro surfaces to dry, though sheltered spots may lag.
The 7-day average humidity of 84% and today's 78% slow evaporation and can leave a thin moisture film on exposed rock faces.
The site's exposed position with 21 km/h northerly winds accelerates surface drying significantly.
Gabbro does not absorb water, so there is no internal moisture risk and drying is purely a surface phenomenon.
Today's northerly wind doesn't blow directly onto the SW-facing boulders, slightly reducing drying efficiency on the main faces.
Recommendations
3
- Visit today or tomorrow and visually/physically check rock surfaces before committing — touch-test for dampness in seams and sheltered overhangs.
- Check tide times before setting out, as some boulders are only accessible around low water and recent swell may affect sea-level problems.
- Bring extra skin tape — the gabbro is notoriously abrasive and any residual moisture softens skin further, accelerating wear.
Marginal — Assess Conditions
70%
60 days ago
Today saw 5.2mm of rain, but gabbro's non-porous nature and the exposed, windy site mean surface moisture should clear quickly. Tomorrow looks dry with moderate northerly winds and dropping humidity, so conditions should be good by morning — but a visual check on arrival is prudent given today's rain and recent coastal humidity.
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 committing to the walk in.
- The gabbro is extraordinarily rough and will shred skin rapidly — bring finger tape and plan shorter sessions, especially in humid conditions when skin softens.
- Cliff-top seepage from grazing land above can create localised wet bands on some boulders for hours after rain, even though the gabbro itself dries fast.
- Landings are poor and uneven across the beach — multiple bouldering pads and a spotter are strongly recommended, particularly on higher problems.
Warnings
2
- Some boulders may retain seepage from cliff-top drainage for several hours after today's rain — visually inspect holds before committing to problems near the cliff base.
- Poor landings across the venue mean wet or sandy pads significantly increase injury risk; ensure pads are dry and well-placed.
Reasoning
Today's 5.2mm rain will have left surface moisture on the non-porous gabbro, but with 26 km/h northerly winds and an exposed coastal position, most surfaces should be dry or nearly dry by late afternoon.
The SW-facing aspect won't benefit from direct sun with today's northerly airflow, but the strong wind exposure and gabbro's zero porosity mean surface water evaporates within hours rather than days.
Gabbro is extremely hard, dense, and non-porous — there is no risk of structural weakening or hold breakage from moisture.
Mid-to-late August is still a good window for coastal climbing in North Wales, though the recent spell of higher humidity (84% average over 7 days) and repeated light rain events suggest an unsettled Atlantic pattern.
Contributing Factors
6
Moderate rain today means rock surfaces are currently wet, though the non-porous gabbro will shed this moisture rapidly.
Gabbro does not absorb water at all, so only surface moisture needs to evaporate — typically a matter of hours in wind.
Consistent winds of 19–27 km/h over coming days will strip surface moisture efficiently.
Elevated coastal humidity over the past week can slow evaporation and leave a thin moisture film, reducing friction despite gabbro's rough texture.
Three consecutive dry days forecast from Aug 22–24 with falling humidity (down to 62%) will produce excellent drying conditions.
A total of 15mm is forecast across Tuesday and Wednesday, which will reset conditions later in the week.
Recommendations
3
- Visit tomorrow (Aug 22) or over the weekend (Aug 23–24) for the best window before the next rain arrives on Tuesday.
- Check tide times carefully — plan your session around low water to access the full range of boulders.
- Bring finger tape and plan a shorter session; the abrasive gabbro combined with residual coastal humidity will wear skin quickly.
Marginal — Assess Conditions
72%
61 days ago
Light showers fell through the morning but the afternoon is forecast dry with strong NW winds; the non-porous gabbro will dry rapidly once rain stops, so a late-afternoon session is plausible but climbers should check surfaces on arrival. Tomorrow brings 5.2 mm of rain making it a poor day, but a sustained dry spell from the 22nd onward should yield excellent conditions.
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 water, so check tide times before committing to the walk-in.
- The gabbro's exceptionally rough texture shreds skin rapidly; bring finger tape and plan shorter sessions, especially in humid conditions when skin softens faster.
- Salt spray and sea-level humidity can leave a thin moisture film on the rock even when it hasn't rained — a quick touch test on arrival is essential.
- The steep walk down to the beach takes 15–20 minutes; factor this into your weather window planning so you're not caught out by incoming tide or returning showers.
Warnings
2
- Semi-tidal venue: some boulders are inaccessible at high water — check tide tables and do not get cut off.
- Tomorrow (Aug 21) is forecast wet with 5.2 mm rain — avoid planning a session for that day.
Reasoning
Today saw scattered light showers through the morning totalling ~2.3 mm, but the afternoon from 10:00 onward is forecast dry; the non-porous gabbro surface will shed this water quickly.
Strong NW winds (25–31 km/h) and the SW-facing aspect catching afternoon sun will dry surface moisture within 1–2 hours of the last shower on this zero-porosity rock.
Gabbro is extremely hard and non-porous — there is no risk of structural weakening or hold breakage from moisture.
Mid-August provides reasonable daylight hours and moderate temperatures; recent humidity has been elevated (85% average over 7 days) which slightly slows surface evaporation but is offset by the strong wind.
Contributing Factors
6
Scattered light rain through the morning (last at ~09:00) has left surface moisture, though totals are modest at 2.3 mm.
NW winds of 25–31 km/h this afternoon will rapidly strip surface moisture from the exposed coastal gabbro.
Zero porosity means water sits on the surface only and cannot penetrate — drying is a matter of hours, not days.
Seven-day average humidity of 85% and salt spray proximity can slow final surface drying and leave a thin moisture film.
The SW-facing boulders catch direct afternoon sun which aids evaporation once cloud breaks in the mid-afternoon.
5.2 mm forecast for August 21st will reset conditions; today's afternoon may be the last dry window before a brief wet spell.
Recommendations
3
- If climbing today, wait until mid-afternoon (after 13:00) to allow the morning showers to dry off, and touch-test holds before committing to problems.
- Check tide times carefully — some boulders will only be accessible around low water, and the walk-in takes 15–20 minutes.
- Bring finger tape and plan a shorter session; the gabbro is brutally abrasive, especially when humidity softens the skin.
Marginal — Assess Conditions
72%
62 days ago
Gabbro at Porth Ysgo is non-porous and dries rapidly, so the light recent rainfall (0.3mm overnight, 1.5mm yesterday) should clear quickly in today's moderate westerly wind — but persistent high humidity and overcast skies mean residual surface dampness and sea-spray film are plausible. A dry window through the afternoon looks good, but climbers should check surfaces on arrival before committing.
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 tables for the Lleyn Peninsula before heading down.
- Coastal salt spray and high ambient humidity (84% average this week) can leave a thin moisture film on gabbro surfaces even without rain — test friction on an easy problem first.
- The SW-facing aspect is sheltered from today's predominantly westerly wind at surface level, but the exposed cliff-top position still aids drying.
- Gabbro's extreme roughness will shred skin quickly, especially in humid conditions when skin is softer — bring tape and plan for shorter sessions.
Warnings
2
- Rain of 4.4mm is forecast for tomorrow (Aug 20) followed by 3.6mm on Aug 21 — today may be your best window this week.
- Some boulders are tide-dependent; do not get caught out by incoming tide on lower problems.
Reasoning
Only 0.3mm fell overnight and 1.5mm yesterday; on non-porous gabbro this represents trivial surface moisture that should evaporate within hours, though coastal humidity in the 70–80% range may slow complete drying.
Strong westerly winds (25–34 km/h) and the SW aspect provide reasonable drying despite heavy cloud cover; the rock surface should be largely dry by late morning.
Gabbro is extremely hard and non-porous — there is zero risk of structural weakening or hold damage from moisture.
Mid-August provides adequate daylight hours and reasonable temperatures (~17°C); conditions are typical for a changeable Welsh summer with frequent light showers.
Contributing Factors
6
Gabbro does not absorb water and dries extremely quickly, so even recent light rain poses no structural concern.
Only 0.3mm overnight and 1.5mm yesterday — trivial amounts that evaporate quickly from non-porous rock.
Average humidity of 84% over the past week with today peaking at 94% overnight can leave a persistent moisture film on rock surfaces.
Sustained westerly winds of 25–34 km/h actively strip surface moisture and accelerate drying.
Cloud cover of 70–100% throughout today limits direct solar radiation on the SW-facing rock.
4.4mm forecast for August 20th means today's window may be the best opportunity before conditions deteriorate.
Recommendations
3
- Aim for the afternoon window (roughly 11:00–18:00) when humidity drops below 75% and wind is strongest — test friction on an easy problem before attempting anything committing.
- Check Lleyn Peninsula tide tables and plan around low tide to access the full range of boulders.
- Bring plenty of finger tape and limit session length — humid conditions soften skin, and gabbro's coarse texture will cause rapid skin loss.
Marginal — Assess Conditions
72%
63 days ago
Light rain fell overnight (0.6mm) but gabbro's non-porous surface dries rapidly, and the exposed, wind-swept site should have dry rock by late morning. However, 100% cloud cover and high humidity (80s%) today will slow evaporation somewhat, so a visual check on arrival is sensible — particularly on shaded or north-facing faces of boulders.
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 tables before making the walk in.
- The gabbro is notoriously abrasive — skin wear is the limiting factor on longer sessions, especially in humid conditions when skin softens; bring finger tape and plan a shorter session.
- Coastal salt spray and high ambient humidity (currently ~80%) can leave a thin moisture film on holds even when it hasn't rained, reducing friction on slopers despite gabbro's inherently rough texture.
- The approach involves a steep walk down to the beach; poor landings on uneven boulders and pebbles make multiple crashpads essential.
Warnings
2
- Coastal salt humidity and overcast skies may leave a thin moisture film on slopers and rounded holds — test friction carefully before attempting committing moves.
- Semi-tidal venue: do not get caught out by an incoming tide; some boulder bases flood and retreat is cut off.
Reasoning
Only 0.6mm of rain fell in the early hours today, and gabbro's zero porosity means surface water will not be absorbed — it sits on the surface ready to be dried by wind and air movement.
Steady westerly wind (~20–26 km/h) on this exposed SW-facing coastal site will strip surface moisture quickly, though persistent 100% cloud cover and humidity in the 75–85% range will slow the final evaporation compared to a sunny day.
Gabbro is extremely hard and non-porous, so there is zero risk of structural weakening or hold breakage from moisture — the only concern is surface slipperiness.
Mid-August is peak summer season with long daylight hours; temperatures are moderate (~17–18°C) and conditions are typical of a changeable Atlantic-influenced spell rather than settled high pressure.
Contributing Factors
6
0.6mm fell between midnight and 01:00, leaving surface moisture on the boulders that needs time to dry.
Gabbro does not absorb water at all, so surface moisture is the only concern and it dries far faster than porous rock types.
Sustained westerly winds of 18–26 km/h across an exposed coastal site will actively strip surface moisture from the rock.
100% cloud cover all day eliminates solar heating, which would otherwise accelerate drying on the SW-facing boulders.
Humidity remains in the 74–94% range today, slowing the final stages of evaporation and potentially leaving a damp film on holds.
Further light rain (0.9mm) is forecast for tomorrow, with heavier rain (3.8mm) on Aug 21, so conditions will remain unsettled before clearing Aug 22.
Recommendations
3
- If climbing today, aim for the late morning to mid-afternoon window (11:00–16:00) when humidity is lowest (~74–79%) and wind is still drying the rock; visually and physically check holds before committing to problems.
- Check tide times — some boulders are only accessible around low water, and combining tide windows with the driest part of the day will give the best session.
- Bring finger tape and plan a shorter session; the rough gabbro combined with slightly humid conditions will shred skin quickly.
Marginal — Assess Conditions
72%
64 days ago
The non-porous gabbro at Porth Ysgo should be structurally fine, but today's very high humidity (91% average, near-saturating overnight) and 100% cloud cover may leave a moisture film on the rock surface, particularly on shaded or north-facing holds. Conditions should improve through the afternoon as humidity drops toward 76–80%, making a late-afternoon session the best window.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- Overnight humidity hit 99% with 100% cloud cover, so condensation/dew on the rock surface is very likely this morning — allow time for wind and any sun breaks to clear it.
- Semi-tidal access means some boulders will only be available around low water; check tide tables for today and plan your session accordingly.
- The SW aspect means the crag benefits from afternoon sun when cloud breaks, which aligns with the forecast clearing to ~62–73% cloud cover between 14:00–16:00.
- Salt spray and coastal humidity can leave a thin moisture film on even non-porous rock, reducing friction despite the gabbro's superb texture.
Warnings
2
- Very high overnight humidity may have left condensation on rock surfaces — test friction carefully on easy moves before committing to harder problems.
- Semi-tidal venue: do not get caught out by an incoming tide on lower boulders.
Reasoning
The last significant rain was 1.2mm on Aug 14, followed by a trace 0.2mm on Aug 16; the gabbro itself will be fully dry, but today's 91–99% humidity and overcast skies likely leave surface condensation or a moisture film.
Moderate westerly winds (~24 km/h) and SW aspect should clear surface moisture through the afternoon as humidity drops to ~76%, giving a reasonable drying window from mid-afternoon onward.
Gabbro is non-porous and extremely hard — there is zero risk of structural weakening or hold breakage from moisture.
Mid-August offers long daylight hours and reasonable temperatures (~18–19°C), though the current spell of high humidity and cloud is typical of Atlantic-influenced Welsh summers.
Contributing Factors
6
Overnight humidity reached 99% with full cloud cover, making surface condensation on the rock very likely through the morning.
Gabbro does not absorb water and dries extremely quickly once surface moisture evaporates, so only surface film is a concern.
Cloud cover drops to 62–73% between 14:00–16:00 with humidity falling to ~76%, creating the best friction window of the day.
Steady westerly winds of 10–24 km/h throughout the day will actively strip surface moisture from the rock.
Only 1.4mm of rain in the last 7 days and just a trace (0.2mm) yesterday, so no significant water to clear from the rock.
The SW-facing coastal setting means persistent marine humidity can maintain a thin moisture film on exposed surfaces even without rain.
Recommendations
3
- Target an afternoon session (14:00–17:00) when humidity is lowest and any cloud breaks allow solar drying of the SW-facing rock.
- Check tide tables before heading down — some of the best boulders are only accessible around low water.
- Bring plenty of chalk and finger tape; the gabbro's abrasive texture will shred skin fast, especially if any residual moisture forces harder gripping.
Likely Safe to Climb
92%
65 days ago
Porth Ysgo's non-porous gabbro is in excellent condition today after two fully dry days, negligible recent rainfall (1.2mm in the last week), and good drying conditions with moderate wind and SW aspect. The rock will be dry and friction should be superb.
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 for Aberdaron/Hell's Mouth before setting out.
- The exceptionally rough gabbro texture shreds skin rapidly — bring finger tape and plan for shorter sessions, especially in warm humid conditions when skin softens.
- Coastal humidity and salt spray can leave a thin moisture film on lower boulders near the waterline even on dry days; wipe holds before committing.
- The approach involves a steep path down to the beach; allow extra time and be aware that cliff-top seepage from grazing land above can make the descent slippery after rain.
Warnings
1
- Some lower boulders may retain residual dampness from sea spray or wave wash — visually inspect holds on tide-dependent problems before climbing.
Reasoning
With only 1.2mm of rain in the past week (last on Aug 14, just 1.2mm) and two fully dry days since, the non-porous gabbro surface will be completely dry.
The SW aspect receives strong afternoon sun in summer, and moderate westerly winds at this exposed coastal site ensure any trace moisture evaporates within hours on gabbro.
Gabbro is extremely hard, dense, and non-porous — there is zero risk of structural weakening or hold breakage from moisture.
Mid-August provides long daylight hours and reasonable temperatures (~18°C), ideal for gabbro bouldering; humidity at 80% today is typical for coastal Wales but does not affect this rock type significantly.
Contributing Factors
5
No rain since Aug 14's light 1.2mm, and non-porous gabbro dries within hours, so the rock is fully dry.
Gabbro does not absorb water, eliminating any concern about internal dampness or structural weakening.
The south-westerly aspect receives strong summer sun and the exposed position ensures consistent wind drying.
Humidity at 80% is typical for this coastal setting and does not materially affect friction on gabbro's extremely rough surface.
2.3mm forecast for Aug 17 means today may be the last fully dry window before several days of intermittent showers.
Recommendations
3
- Climb today if possible — this is likely the last clean dry window before a spell of intermittent showers over the coming days.
- Check tide times for the Lleyn Peninsula coast and plan your session around low water to access the full range of boulders.
- Bring finger tape and a soft brush; the gabbro is brutally abrasive and shorter focused sessions will preserve skin for future days.
Climbing Outlook