Climbing Forecast › North Wales — Llanberis Pass › Cromlech Boulders

NORTH WALES — LLANBERIS PASS · RHYOLITE

Cromlech Boulders weather & climbing conditions

Caution — drying out or marginal

Right now

Temp6°C
Wind19 km/h
Gusts22 km/h
Humidity90.82%
Rain 48hdry
Last rainNone recent

Assessment

No recent rain
Humidity 91% — potential fog
High humidity (90.82%) — rhyolite friction compromised, particularly for bouldering
Humidity 90.82% — potential fog/cloud, rock may be damp from condensation

7-day forecast

Scroll through each day — hourly detail is shown inline.

Today Saturday 31 October
Caution
Temp6°C
Raindry
Wind19 km/h
Gusts22 km/h
Humidity91%
No recent rainHumidity 91% — potential fog
  • Damp mountain air — upper pitches may stay greasy
Time °C Rain Wind (km/h) Gust Hum
15:00 6° dry 19 22 90.82%
18:00 6° dry 12 18 89.13%
21:00 6° dry 16 18 88.75%
Sun Sunday 1 November
Poor
Temp4°C
Rain0.7mm
Wind27 km/h
Gusts36 km/h
Humidity98%
0.7mm rain forecastHumidity 98% — likely fog/cloud
  • Wet rhyolite is slippery; seepage from grass above can linger
  • Breezy — helps drying
Time °C Rain Wind (km/h) Gust Hum
06:00 5° 0.4mm 29 36 99.97%
09:00 4° 0.3mm 30 40 99.49%
12:00 4° dry 26 36 97.94%
15:00 4° dry 28 36 97.58%
18:00 4° dry 28 35 99.04%
21:00 4° dry 28 36 97.71%
Mon Monday 2 November
Caution
Temp2°C
Raindry
Wind30 km/h
Gusts45 km/h
Humidity86%
Should be dryWindy — 30 km/h, gusts 45 km/h
  • Cold mountain conditions — pack warm belay layers
  • Damp mountain air — upper pitches may stay greasy
  • Breezy — helps drying
Time °C Rain Wind (km/h) Gust Hum
06:00 0° dry 34 43 95.35%
09:00 1° dry 36 46 94.75%
12:00 2° dry 29 42 86.11%
15:00 3° dry 31 45 86.24%
18:00 2° dry 30 43 94.39%
21:00 1° dry 33 47 93.63%
Tue Tuesday 3 November
Caution
Temp3°C
Raindry
Wind33 km/h
Gusts53 km/h
Humidity89%
Should be dryWindy — 33 km/h, gusts 53 km/h
  • Cold mountain conditions — pack warm belay layers
  • Damp mountain air — upper pitches may stay greasy
  • Breezy — helps drying
Time °C Rain Wind (km/h) Gust Hum
06:00 0° dry 35 49 97.27%
09:00 1° dry 36 52 95.08%
12:00 2° dry 33 53 88.75%
15:00 3° dry 33 51 88.97%
18:00 2° dry 37 53 92.63%
21:00 2° dry 40 57 92.69%
Wed Wednesday 4 November
Poor
Temp3°C
Raindry
Wind40 km/h
Gusts62 km/h
Humidity84%
Should be dryWind 40 km/h, gusts 62 km/h — too windy
  • Cold mountain conditions — pack warm belay layers
  • Very windy — consider sheltered alternatives
Time °C Rain Wind (km/h) Gust Hum
06:00 1° dry 41 59 95.19%
09:00 1° dry 43 63 93.11%
12:00 2° dry 40 62 86.36%
15:00 3° dry 40 60 82.61%
18:00 2° dry 45 64 87.56%
21:00 1° dry 49 70 89.85%
Thu Thursday 5 November
Poor
Temp2°C
Raindry
Wind39 km/h
Gusts63 km/h
Humidity84%
Should be dryWind 39 km/h, gusts 63 km/h — too windy
  • Cold mountain conditions — pack warm belay layers
  • Very windy — consider sheltered alternatives
Time °C Rain Wind (km/h) Gust Hum
06:00 0° dry 46 65 94.12%
09:00 1° dry 47 68 91.26%
12:00 2° dry 41 63 84.26%
15:00 2° dry 38 57 84.37%
18:00 2° dry 41 57 90.2%
21:00 1° dry 41 57 91.79%
Fri Friday 6 November
Caution
Temp2°C
Raindry
Wind25 km/h
Gusts42 km/h
Humidity90%
Should be dryHumidity 90% — potential fog
  • Cold mountain conditions — pack warm belay layers
  • Damp mountain air — upper pitches may stay greasy
  • Breezy — helps drying
Time °C Rain Wind (km/h) Gust Hum
06:00 0° dry 32 45 95.6%
09:00 1° dry 31 45 93.13%
12:00 1° dry 27 42 89.27%
15:00 2° dry 24 36 90.42%
18:00 1° dry 24 33 94.93%
21:00 1° dry 23 31 96.39%
Sat Saturday 7 November
Caution
Temp2°C
Raindry
Wind18 km/h
Gusts31 km/h
Humidity90%
Should be dryHumidity 90% — potential fog
  • Cold mountain conditions — pack warm belay layers
  • Damp mountain air — upper pitches may stay greasy
Time °C Rain Wind (km/h) Gust Hum
06:00 0° dry 20 27 97.9%
09:00 0° dry 21 29 95.69%
12:00 2° dry 19 31 89.73%
15:00 2° dry 17 27 89.6%

About Cromlech Boulders

One of the most internationally famous roadside bouldering venues in the world — a scattered field of huge fallen rhyolite/tuff blocs below Dinas Cromlech in the Llanberis Pass. Part of Welsh climbing lore since the Joe Brown era — you can literally step out of the car and start on the easier problems. Boulders face multiple directions across the scatter, so sun or shade can always be found. Best in cool, dry conditions: friction on the coarser rhyolite blocs suffers in warm summer sun.

Region
North Wales — Llanberis Pass
Rock type
Rhyolite
Aspect
mixed-facing
Altitude
380m
Exposure
medium
Seepage
low

Other crags in this region

Carreg WastadClogwyn y GrochanCraig DduCyrn LasDinas CromlechDinas Mot