Condition Analysis
AI-powered assessment using site data and 14-day weather history
Today has seen 0.6mm of light rain with high humidity (88%), but the rock had three excellent drying days prior (Aug 11–13) with warm temperatures and low humidity. The south-facing aspect and partial wind exposure should allow surface moisture to clear relatively quickly, but conditions need visual confirmation on arrival given today's dampness and the unsettled forecast ahead.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The 15–20 minute uphill approach means conditions at the boulders may differ from what you see at road level — the higher altitude (300m) can hold more moisture and cloud contact.
- The stratified rhyolite formations can create natural drainage channels and ledges where water pools after even light rain, particularly on slab features and horizontal breaks.
- South-facing aspect is a significant advantage here, maximising solar drying through the day, but the Llanberis Pass funnels moist westerly/south-westerly air which can keep humidity elevated.
- Some problems in more sheltered alcoves or beneath overhangs may retain seepage longer than the open faces, so check holds individually on steeper featured terrain.
Warnings
2
- Heavy rain forecast for August 18 (21mm) followed by 8mm on Aug 19 — avoid climbing on those days as friction will be severely compromised.
- Wet rhyolite is extremely slippery despite being structurally sound — do not attempt friction-dependent slabs if any surface moisture is present.
Reasoning
Today's 0.6mm of rain on top of 88% humidity means surfaces are likely damp right now, though the preceding three dry, warm days (up to 30°C on Aug 12) would have thoroughly dried the rock before today's shower.
The south-facing aspect with moderate wind exposure should clear today's light surface moisture within a few hours of any sunshine, but with overcast humid conditions today, drying will be sluggish.
Rhyolite is non-porous and does not suffer structural weakening when wet — no risk of hold breakage from moisture.
Mid-August provides long daylight hours and reasonable temperatures for drying, though the current unsettled spell with an approaching heavy front (21mm on Aug 18) signals deteriorating conditions.
Contributing Factors
6
0.6mm of rain today combined with 88% humidity means rock surfaces are likely damp currently.
Three consecutive dry days (Aug 11–13) with temperatures reaching 30°C and humidity as low as 51% would have thoroughly dried the rock before today.
The southerly aspect maximises solar exposure through summer days, accelerating surface drying on non-porous rhyolite.
Humidity of 88% today significantly slows evaporation and may leave a film of moisture on rock surfaces.
Persistent light showers through Aug 15–17 followed by heavy rain (21mm on Aug 18) mean conditions will deteriorate significantly from mid-week.
Partial wind exposure at 300m provides some airflow to assist surface drying between showers.
Recommendations
3
- If climbing today, wait until afternoon to allow any morning dampness to clear and visually inspect holds for moisture before committing to friction-dependent moves.
- The best window this week is likely today or early tomorrow morning before the next shower — conditions deteriorate sharply from Aug 17 onward.
- Bring a towel and soft brush to dry holds if needed, and prioritise steeper overhanging problems where water runs off rather than pooling.
Previous Analyses
Likely Safe to Climb
90%
2 days ago
Three consecutive dry days, warm temperatures, and south-facing aspect have dried the rhyolite thoroughly; today is an excellent day for bouldering at Wavelength. Conditions will deteriorate from tomorrow as a wet spell moves in, so today represents the best window for the foreseeable future.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The south-facing aspect at 300m catches strong summer sun, meaning surface moisture from the light showers on Aug 9–10 (0.5mm total) will have evaporated well within the three dry days since.
- The 15–20 minute uphill approach means conditions at the boulders can differ from the road — the elevated, exposed position aids drying but can also catch cloud and hill fog earlier than the valley floor.
- Some of the stratified rhyolite formations can hold seepage in horizontal cracks and overlap features even when main faces are dry — check these areas before committing to problems that use them.
- A significant storm is forecast for Aug 17 (54.5mm) which will saturate the hillside; drainage and seepage may persist for days after on certain lines.
Warnings
1
- A major storm (54.5mm) is forecast for August 17 — avoid the hillside that day and plan for extended seepage afterwards.
Reasoning
Only 0.5mm fell in the last 7 days (tiny amounts on Aug 9–10), followed by three fully dry days including two warm days reaching 24–30°C with moderate humidity, leaving the non-porous rhyolite surface confidently dry.
The south-facing aspect receives strong August solar radiation, and moderate winds (14–17 km/h) have aided evaporation — the negligible recent precipitation would have dried within hours on this rock type and aspect.
Rhyolite is non-porous and does not suffer structural weakening from moisture; no freeze-thaw risk in summer — hold breakage risk is negligible.
Mid-summer provides long daylight hours, warm temperatures, and good drying potential; today's 26°C peak and low humidity (46–55% midday) offer ideal friction conditions.
Contributing Factors
5
No meaningful rain since Aug 10 (0.1mm), with three fully dry days allowing complete surface drying on non-porous rhyolite.
Temperatures of 24–30°C over the last two days combined with direct southern sun exposure ensure rapid and thorough evaporation.
Humidity drops to 46% at peak hours today, providing excellent friction conditions on the textured rhyolite.
2.3mm expected tomorrow and persistent wet weather through the week — today is the last good window before conditions deteriorate significantly.
Humidity climbs above 80% after 20:00 with full cloud cover, so best friction is available before late afternoon.
Recommendations
3
- Climb today if possible — this is the best window before a prolonged wet spell arrives tomorrow.
- Target the midday-to-late-afternoon window (11:00–17:00) when humidity is lowest and friction is at its peak.
- Check horizontal crack systems and overlap features for lingering seepage before pulling on, even though main faces should be fully dry.
Likely Safe to Climb
90%
3 days ago
Conditions at Wavelength Boulders are excellent today. Two full dry days following only trace precipitation, combined with today's hot sunshine (29°C), low humidity (40s%), and a south aspect mean the rhyolite will be thoroughly dry with superb friction.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The south-facing aspect and 300m altitude mean the boulders receive strong solar radiation throughout the day, and today's clear skies and near-30°C temperatures will have baked any residual moisture off the rock.
- Some of the stratified rhyolite formations can hold seepage in horizontal breaks after prolonged wet spells — the recent run of light drizzle days (25 Jul–1 Aug) was minor enough that this is unlikely to be an issue now.
- The 15–20 minute uphill approach means conditions at the boulders can differ from what you see at road level in the Pass — the higher elevation catches more breeze, aiding drying.
- A significant weather change is forecast from 14 August onwards with heavy rain (up to 18mm on the 17th) and high winds, so today and tomorrow represent the best window this week.
Warnings
1
- A major weather deterioration is forecast from 14 August with heavy rain and strong winds — do not assume this window will extend beyond tomorrow.
Reasoning
The last meaningful rain was 11.4mm on 4 August (8 days ago), followed by 8.4mm on 5 August; since then only trace amounts (≤0.4mm) have fallen, and the rock has had two completely dry days with today reaching 29°C and sub-50% humidity.
The south aspect receives direct solar heating all day, and with moderate wind exposure and today's exceptional warmth, any trace surface moisture will have evaporated rapidly — rhyolite's non-porous nature means drying is purely a surface phenomenon.
Rhyolite is non-porous and does not suffer structural weakening from moisture; there is no hold breakage risk from recent weather.
Mid-August is prime summer season with long daylight hours and warm temperatures; today's 29°C is unusually warm for 300m in Snowdonia, providing ideal friction conditions once the hottest hours pass.
Contributing Factors
5
No significant rain since 5 August (7 days), with only trace precipitation (≤0.4mm) on isolated days since, giving ample drying time for non-porous rhyolite.
Today's 29°C peak and humidity dropping to 39% provide exceptional evaporative conditions, ensuring any residual dampness is eliminated.
The south aspect maximises solar exposure throughout the day, accelerating surface drying and warming the rock.
From 14 August, significant rain (up to 18.4mm on 17th) and high winds (40+ km/h) are forecast, closing the current dry window.
Partial wind exposure at 300m provides airflow across the boulders, aiding evaporation without creating hazardous gusts today.
Recommendations
3
- Climb today or tomorrow (13 Aug) to take advantage of the current dry, warm window before the frontal system arrives on the 14th.
- Afternoon and evening sessions will offer the best friction as temperatures cool from the mid-afternoon peak — the rock may feel slightly greasy in the hottest hours above 28°C.
- Carry water and sun protection for the uphill approach; conditions are unusually warm for this altitude.
Marginal — Assess Conditions
72%
5 days ago
The last significant rain was 11.4mm on Aug 4th and 8.4mm on Aug 5th, followed by two full dry days and today (also dry), giving the south-facing rhyolite reasonable drying time. However, scattered light showers on Aug 9th (0.2mm) and persistently high humidity in the 70–80% range mean some seepage or residual dampness in sheltered spots is possible — a visual check on arrival is warranted.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The 15–20 minute uphill approach means conditions at the boulders may differ from what you see at road level — cloud base can sit on the boulders at 300m even when the Pass floor looks clear.
- South-facing aspect receives strong afternoon sun in summer, which helps dry exposed faces quickly, but overhanging or north-facing facets of individual boulders can hold seepage for longer.
- The stratified rhyolite formations can channel water along horizontal bedding planes, creating localised seepage lines that persist after rain even on otherwise dry rock.
- High humidity (averaging 77% over the past week) at this altitude can cause condensation on rock surfaces in the early morning — conditions improve markedly from late morning onward.
Warnings
2
- Early morning condensation is likely at 300m given overnight humidity near 90% — do not assume the rock is dry before mid-morning.
- Rain returns on Aug 14–15 with ~6mm forecast; plan sessions for Aug 11–13 to catch the best window.
Reasoning
The rock received ~20mm of rain over the past week (mostly Aug 4–5), with only trace amounts since, and the non-porous rhyolite surface should be largely dry after 4+ days, though seepage lines along stratified features may still be damp.
Two full dry days with moderate westerly/southerly winds and the south-facing aspect have provided reasonable drying, but average humidity of 77% and temperatures around 15–20°C have slowed evaporation compared to ideal conditions.
Rhyolite is non-porous and does not suffer structural weakening when wet — hold breakage from moisture is not a concern.
Mid-summer provides long daylight hours and generally warm temperatures, though the recent unsettled spell with higher humidity is typical of a Welsh August and slows surface drying at 300m altitude.
Contributing Factors
6
11.4mm on Aug 4th and 8.4mm on Aug 5th totalling ~20mm in two days is substantial, though 4–5 days have now elapsed since.
Four days since the last significant rain with no more than trace precipitation (0.2mm on Aug 9th), giving south-facing rhyolite adequate surface drying time.
Humidity has averaged 77% over the past week, slowing evaporation and increasing the risk of early-morning condensation on the rock.
The southerly aspect receives strong direct sunlight through the middle of the day in August, significantly accelerating surface drying.
Today is fully dry with humidity dropping to the mid-50s by afternoon and partial sun breaks, allowing further drying through the day.
Only 0.2mm fell yesterday — negligible for non-porous rock and unlikely to have re-wetted surfaces meaningfully.
Recommendations
3
- Aim for an afternoon session today (after midday) when solar heating and dropping humidity will have maximised surface drying.
- Check seepage lines along the horizontal stratified features before committing to problems — these can remain damp even when surrounding rock is dry.
- Tomorrow (Aug 11) and the following two days look excellent with warm, dry, lower-humidity conditions — consider targeting these days for the best friction.
Marginal — Assess Conditions
72%
5 days ago
The boulders have had 4 consecutive dry days following significant rain (nearly 20mm on Aug 4–5), and the south-facing aspect with partial wind exposure should have dried most surfaces well. However, humidity has remained moderately high (68–76%) and temperatures have been below average, so sheltered or north-facing faces of individual boulders and seepage lines may still hold residual moisture.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The 15–20 minute uphill approach means conditions at the boulders may differ from what you observe at road level in the Pass — check rock surfaces on arrival before committing.
- Stratified rhyolite formations can trap moisture in horizontal seams and overlaps, creating localised seepage even when main faces appear dry.
- South-facing aspect receives excellent summer sun, but individual boulder faces oriented north or tucked into hollows will dry significantly slower.
- High humidity days (87%+ forecast for Aug 13–14) can cause condensation on rock surfaces at 300m altitude, particularly in early morning and evening.
Warnings
2
- Wet rhyolite is dangerously slippery — if any surface feels greasy or damp, do not attempt the problem.
- Seepage from horizontal stratification bands may persist even when surrounding rock appears dry; test holds carefully on overhanging or featured problems.
Reasoning
After 19.8mm of rain on Aug 4–5, four full dry days with south-facing sun and moderate wind should have cleared surface moisture from most exposed faces, though residual dampness may linger in seepage lines and shaded recesses.
The south aspect and partial wind exposure provide above-average drying, but temperatures have been cool (15–20°C) and humidity moderate-to-high (68–76%), slowing evaporation somewhat compared to ideal summer conditions.
Rhyolite is non-porous and does not suffer structural weakening when wet, so hold breakage is not a concern.
Mid-summer provides the longest daylight hours and best solar angles for drying south-facing rock, though the recent spell has been cooler and more humid than typical for August.
Contributing Factors
6
Four consecutive rain-free days since the last significant precipitation should be sufficient for surface drying on non-porous rhyolite with good aspect.
Nearly 20mm fell across Aug 4–5, which is a substantial soaking that can leave lingering moisture in cracks and seepage features.
The southerly aspect receives strong summer sun, and partial wind exposure aids evaporation, giving above-average drying rates.
Humidity has averaged around 74% over the past week, which slows drying and can leave a damp film on rock surfaces, particularly at altitude.
Average temperatures around 16–18°C are below typical August levels, reducing the rate of evaporation.
Rhyolite does not absorb water, so the concern is surface friction rather than structural damage, and surface moisture clears relatively quickly.
Recommendations
3
- Visually and physically check holds on arrival — run your hand across key surfaces to test for dampness or greasy film before committing to problems.
- Prioritise south-facing, wind-exposed boulder faces first; save shaded or recessed problems for later in the day once the sun has warmed the rock.
- Conditions should improve markedly from Aug 11 onward as temperatures rise and humidity drops — consider delaying a day or two for optimal friction.
Marginal — Assess Conditions
70%
6 days ago
After significant rain on Aug 4–5 (nearly 20mm combined), three dry days with a south-facing aspect and moderate wind should have dried the main boulder surfaces. However, humidity has remained fairly high and some seepage or sheltered damp patches may persist, so a visual check on arrival is advisable.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The 15–20 minute uphill approach means conditions at the boulders may differ from what you observe at road level in the Pass — carry a towel and brush to test surfaces on arrival.
- South-facing aspect at 300m catches good afternoon sun, which significantly aids drying of the main faces, but any north-facing or overhanging features will retain moisture longer.
- The stratified rhyolite formations can channel seepage along bedding planes after prolonged wet spells — the recent run of light rain from July 25 to Aug 5 may feed lingering seepage lines on some problems.
- Llanberis Pass can be subject to low cloud and mist that deposits condensation even without recorded rainfall — the elevated humidity readings (73% average) suggest this may be a factor.
Warnings
2
- Rain is forecast for Aug 9 (2.1mm) which will reset drying — plan your session for today (Aug 8) afternoon if possible.
- Do not trust surface appearance alone on overhanging or north-facing features; test friction with your palm before pulling on.
Reasoning
The main south-facing surfaces should be largely dry after three full dry days, but the preceding wet spell (20.4mm over seven days including two heavier days) and persistent humidity around 68–75% mean some sheltered or seepage-fed areas may still hold dampness.
Three consecutive dry days with south-facing sun exposure, moderate southerly wind (~17 km/h), and temperatures reaching 18–20°C provide reasonable but not exceptional drying conditions for non-porous rhyolite.
Rhyolite is non-porous and does not absorb water, so there is no structural weakening or hold breakage risk from the recent rain.
Mid-summer provides long daylight hours and adequate solar radiation for drying, though recent temperatures have been below average for August and humidity has been elevated.
Contributing Factors
6
No precipitation since Aug 5, giving surface moisture ample time to evaporate from non-porous rhyolite.
The south aspect maximises solar heating in summer, accelerating surface drying significantly.
Nearly 20mm fell across two days, which can feed seepage lines and saturate surrounding vegetation and soil for several days.
Average humidity of 73% over the past week slows evaporation and can produce condensation on rock surfaces, especially overnight and in the morning.
Partial wind exposure with consistent 14–18 km/h winds aids surface evaporation.
Light but persistent rain from July 25 to Aug 5 saturated the ground and may sustain seepage from above even after surface rock dries.
Recommendations
3
- Visit in the afternoon when the south-facing boulders have had maximum sun exposure and any overnight condensation has burned off.
- Carry a towel and boar's-hair brush to test and prepare surfaces — check seepage lines along the distinctive bedding planes before committing to harder problems.
- If surfaces feel greasy or friction is noticeably poor, back off and return after another dry day; rhyolite friction is superb when dry but drops sharply when damp.
Marginal — Assess Conditions
72%
7 days ago
The last significant rain (11.4mm + 8.4mm) fell on August 4–5, followed by two dry days with moderate winds; the south-facing rhyolite surfaces should be largely dry, but high humidity and the recent heavy rain mean some sheltered or shaded features could retain residual moisture. A visual check on arrival is recommended before committing to climb.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The 15–20 minute uphill approach means conditions at the boulders may differ from what you observe at road level — the 300m altitude brings cooler temps and potentially more lingering moisture in sheltered spots.
- The stratified formations at Wavelength create horizontal ledges and overlapping layers that can trap seepage and stay damp longer than smooth faces, particularly after nearly 21mm of rain in two days.
- South-facing aspect is a significant advantage here — direct solar radiation through the middle of the day will have been actively drying surfaces since the rain stopped on August 5th.
- Some lower or north-facing facets of individual boulders will dry considerably slower than the main south-facing walls; check these carefully before pulling on.
Warnings
1
- Rhyolite friction drops significantly when damp — if holds feel greasy or polished, back off; a slip on these boulders at 300m with a steep approach could result in a serious ankle or back injury.
Reasoning
After 19.8mm of rain on Aug 4–5, followed by two full dry days with moderate westerly winds and today showing 0mm, the non-porous rhyolite surfaces should be predominantly dry but sheltered crevices and horizontal ledges may still harbour residual moisture.
Two days of drying with moderate winds (18–24 km/h) and a south-facing aspect at 300m altitude should be sufficient for exposed rhyolite faces, though humidity has remained in the 73–83% range which slows evaporation from sheltered features.
Rhyolite is non-porous and does not suffer structural weakening when wet; there is no risk of hold breakage from moisture.
Mid-summer conditions provide long daylight hours and reasonable solar angles for drying this south-facing venue, though recent temperatures have been below average for August at around 16–17°C.
Contributing Factors
6
Nearly 20mm fell across August 4–5, which is a significant soaking that requires adequate drying time even on non-porous rock.
Two consecutive dry days with moderate wind should be sufficient to clear surface moisture from most exposed rhyolite faces.
The south-facing orientation maximises solar drying through the day, significantly accelerating moisture evaporation from rock surfaces.
Humidity has averaged 74% over the past week and remains around 73% today, which slows evaporation and can leave a film of moisture on textured rock.
Partial wind exposure with 15–18 km/h winds aids surface drying, though not as effectively as a fully exposed venue.
The distinctive layered formations create ledges and crevices that trap water and dry more slowly than smooth vertical faces.
Recommendations
3
- Visit in the afternoon when the south-facing rock has had maximum solar exposure and surface temperatures are highest.
- Inspect holds carefully for residual dampness, especially on horizontal breaks, scooped features, and any north-facing facets of boulders.
- Prioritise problems on the most exposed, sun-facing walls first; leave shaded or recessed problems for another day if they feel greasy.
Marginal — Assess Conditions
62%
9 days ago
Heavy rain on Aug 4–5 (nearly 20mm) was followed by a dry day today, but high humidity and overcast skies have limited drying. The south-facing aspect and moderate wind should have cleared most surface moisture by this afternoon, but sheltered faces and seepage zones may still be damp — visually assess before climbing.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The 15–20 minute uphill approach means conditions at the boulders can differ significantly from what you see at road level in the Llanberis Pass — the higher altitude (300m) keeps temperatures cooler and humidity higher.
- Some of the stratified rhyolite formations have horizontal breaks and overlapping layers that can trap and channel seepage for a day or more after heavy rain, even though the rock itself is non-porous.
- The south-facing aspect is a major asset for drying but today's persistent 100% cloud cover through midday has greatly reduced solar input, limiting that advantage.
- The boulders sit above the Climbers' Club hut on an open hillside where westerly wind aids drying, but recessed faces and north-facing sides of individual boulders will dry much more slowly.
Warnings
2
- Rhyolite becomes very slippery when wet — friction-dependent slab problems and smears should be avoided if any surface moisture is detected.
- Further light rain (1.1mm) is forecast for tomorrow (Aug 7), which will reset drying progress.
Reasoning
Nearly 20mm fell on Aug 4–5, and today is only the first fully dry day; while rhyolite does not absorb water, surface moisture, seepage from cracks, and residual dampness in sheltered spots are likely still present.
One dry day with moderate westerly wind (~19 km/h) and south aspect would normally clear surface moisture on exposed faces, but persistent cloud cover and 77% average humidity today have significantly slowed evaporation.
Rhyolite is non-porous and does not suffer structural weakening when wet, so hold breakage is not a concern.
Mid-summer provides long daylight hours and reasonable warmth, but the recent shift to cooler, more unsettled Atlantic weather (15–17°C) has reduced drying potential compared to the warm spell earlier in July.
Contributing Factors
7
11.4mm on Aug 4 and 8.4mm on Aug 5 delivered nearly 20mm in two days, saturating surfaces and filling seepage lines.
Today is the first dry day after the rain, providing limited drying time for a site at 300m altitude.
Humidity has averaged around 77% today with heavy cloud cover through midday, significantly slowing evaporation.
The south aspect maximises any solar radiation that breaks through, and afternoon clearing (65–49% cloud from 16:00–17:00) should help dry exposed surfaces.
Winds around 15–19 km/h from the west provide reasonable airflow across the hillside to aid surface evaporation.
Rhyolite does not absorb water, so drying is purely a surface and seepage phenomenon — no internal dampness risk.
Cloud cover drops to 49–65% between 16:00–17:00 today, allowing some direct solar drying on south-facing surfaces.
Recommendations
3
- If visiting today, wait until mid-to-late afternoon (after 15:00) when cloud cover drops and humidity falls to ~61%, then physically touch holds before committing to problems.
- Prioritise exposed, south-facing walls and slabs that catch the most wind and any afternoon sun — avoid recessed or north-facing boulder faces which will still be damp.
- Carry a towel and brush but accept that some problems (especially those with horizontal breaks or seepage lines) may not be in condition today.
Do Not Climb
92%
11 days ago
Wavelength Boulders are currently wet from persistent rain throughout today (8.7mm), with humidity near saturation (90–97%) and 100% cloud cover preventing any meaningful drying. The rock will be slippery and conditions are unsuitable for climbing today.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The 15–20 minute uphill approach means climbers commit significant effort before seeing conditions — check forecasts carefully before setting out.
- The south-facing aspect is an advantage for drying, but today's 100% cloud cover and extreme humidity negate any solar benefit.
- The stratified rhyolite formations can hold surface water in horizontal features and seepage lines longer than smooth faces, even though the rock itself is non-porous.
- At 300m altitude, low cloud and mist are common in the Llanberis Pass during unsettled spells, keeping surfaces damp even between rain showers.
Warnings
2
- Wet rhyolite is extremely slippery — friction-dependent boulder problems become dangerously insecure.
- The uphill approach will be muddy and slippery; take care on the hillside path.
Reasoning
The rock is currently wet from repeated showers throughout the day (8.7mm total), with humidity at 90–97% preventing any evaporation.
Despite moderate southerly winds (19–23 km/h), the near-saturation humidity and complete cloud cover mean negligible drying is occurring; the south aspect provides no benefit under overcast skies.
Rhyolite is non-porous so there is no structural damage risk from moisture, but surface friction is severely compromised when wet.
Mid-summer should offer the best drying conditions, but this unsettled spell with frequent light rain and high humidity is atypical and has kept conditions persistently damp for over a week.
Contributing Factors
6
8.7mm of precipitation spread across most of the day leaves all rock surfaces thoroughly wet.
Humidity has been 90–97% for most of today, preventing any meaningful evaporative drying.
100% cloud cover throughout the day eliminates solar heating that would otherwise help the south-facing boulders dry.
Southerly winds of 19–23 km/h provide some airflow, but cannot overcome the saturated air mass to dry the rock.
Light but persistent precipitation since July 25th (11.1mm in 7 days) means the boulders have had little opportunity to fully dry out.
Rhyolite does not absorb water, so once conditions improve, surface drying will be relatively quick.
Recommendations
3
- Do not climb today — the rock is wet and slippery with no drying window available.
- Watch for August 7th as a potential dry window if the forecast holds, but check conditions on arrival given the preceding rain on August 6th.
- If visiting during this unsettled spell, have a backup plan such as an indoor wall or lower-altitude sheltered crags that dry faster.
Marginal — Assess Conditions
62%
12 days ago
After a week of light but persistent showers, this morning's dry spell with clearing skies and warm temperatures (up to 25°C) should dry the south-facing rhyolite surfaces through the midday hours, but rain is forecast to return from around 17:00 today and a very wet spell begins tomorrow. A climbing window exists roughly 10:00–16:00 today if the rock looks and feels dry on arrival.
Based on weather conditions only — does not cover bird nesting restrictions or other access issues.
- The 15–20 minute uphill approach means conditions at the boulders may differ from the road — check rock surfaces carefully on arrival as seepage from the hillside above can linger on lower features.
- South-facing aspect at 300m receives strong summer solar radiation from mid-morning, which significantly accelerates surface drying on rhyolite between showers.
- The stratified rhyolite formations can trap moisture in horizontal cracks and overlaps even when main faces appear dry — test friction on a warm-up problem before committing to harder lines.
- Light drizzle has been frequent over the past week (4.6mm across multiple days) so moss and lichen in shaded corners may be unusually slippery for summer.
Warnings
2
- Rain is forecast to return this evening and persist heavily through the coming week — do not assume conditions will hold past late afternoon.
- The approach path will be muddy from recent rain; take care on the steep sections, especially on descent if showers arrive early.
Reasoning
The rock received only 0.1mm yesterday and light overnight drizzle (0.1mm at 01:00), but the preceding week saw repeated light rain totalling ~4.6mm, keeping ambient humidity elevated; surfaces are likely damp this morning but drying rapidly as sun breaks through.
Clear skies forecast from 09:00–13:00 with temperatures reaching 25°C and moderate SE winds on a south-facing aspect should dry exposed rhyolite surfaces within 2–3 hours, giving a usable window before evening rain arrives at ~17:00.
Rhyolite is non-porous and does not suffer structural weakening when wet; there is no hold-breakage or rock-damage concern here.
Mid-summer conditions mean long daylight hours and warm temperatures that aid drying, though the current unsettled Atlantic pattern with high humidity (77% average last 7 days) slows evaporation compared to the exceptional dry spell earlier in July.
Contributing Factors
6
Clear skies and warm temperatures (21–25°C) from approximately 09:00–16:00 provide several hours for surface drying and climbing.
Multiple days of light precipitation (4.6mm over the past week across five separate days) have kept the rock and surrounding ground consistently moist.
The south aspect maximises summer solar heating, accelerating evaporation of surface moisture on exposed faces.
Showers are forecast from 17:00 onwards (totalling ~2mm), closing the climbing window and re-wetting surfaces.
Average humidity of 77% over the past week and 62% today overall slows drying and can leave a film of moisture on textured surfaces.
Heavy rain is forecast for the next 5 days (39.3mm total), meaning today may be the last viable session for nearly a week.
Recommendations
3
- Aim for the 10:00–16:00 window today; test friction on easy problems first and abort if the rock feels glassy or greasy.
- Be packed up and heading down by 16:30 as showers are forecast from 17:00 and the descent path will become slippery.
- Bring a towel and soft brush to dry any residual dampness on holds, and avoid problems in shaded alcoves or near seepage lines where moisture will persist.
Climbing Outlook