Climbing Forecast › South Wales — Black Mountains › Cwmyoy Boulders

SOUTH WALES — BLACK MOUNTAINS · SANDSTONE · bird ban

Cwmyoy Boulders weather & climbing conditions

Caution — drying out or marginal

Right now

Temp7°C
Wind10 km/h
Gusts16 km/h
Humidity93.6%
Rain 48hdry
Last rainNone recent

Assessment

No recent rain
Humidity 94% — potential fog
Humidity 93.6% — potential fog/cloud, rock may be damp from condensation
Check sandstone is genuinely dry — condensation can wet the surface

7-day forecast

Scroll through each day — hourly detail is shown inline.

Today Sunday 1 November
Caution
Temp9°C
Raindry
Wind16 km/h
Gusts16 km/h
Humidity94%
No recent rainHumidity 94% — potential fog
  • Hard sandstone climbs well when dry
Time °C Rain Wind (km/h) Gust Hum
09:00 7° dry 10 — 93.6%
10:00 8° dry 14 — 94.5%
11:00 8° dry 17 — 94.5%
12:00 9° dry 17 — 95.3%
13:00 10° dry 17 — 95.3%
14:00 10° dry 18 — 95.1%
15:00 11° dry 17 — 89.3%
16:00 10° dry 16 — 91.4%
17:00 9° dry 14 — 96.9%
18:00 9° dry 15 — 97.2%
19:00 10° dry 18 — 96.4%
20:00 10° dry 18 — 95.8%
21:00 10° dry 18 — 95.7%
Mon Monday 2 November
Good
Temp9°C
Raindry
Wind21 km/h
Gusts—
Humidity77%
No recent rain
  • Hard sandstone climbs well when dry
  • Breezy — helps drying
Time °C Rain Wind (km/h) Gust Hum
06:00 5° dry 16 — 95.4%
07:00 4° dry 16 — 95.8%
08:00 5° dry 17 — 96.4%
09:00 6° dry 20 — 91.4%
10:00 7° dry 22 — 89%
11:00 8° dry 24 — 82.1%
12:00 9° dry 24 — 77.5%
13:00 9° dry 23 — 74.9%
14:00 9° dry 20 — 72.8%
15:00 9° dry 19 — 70.4%
16:00 9° dry 18 — 72.2%
17:00 8° dry 19 — 74.1%
18:00 8° dry 19 — 75.9%
19:00 8° dry 18 — 76.3%
20:00 8° dry 18 — 78.9%
21:00 6° dry 17 — 84.7%
Tue Tuesday 3 November
Poor
Temp8°C
Rain1mm
Wind20 km/h
Gusts—
Humidity92%
1.3mm rain forecastDo not climb wet sandstoneHumidity 92% — potential fog
  • Wet sandstone is slippery — let the rock dry before leading
Time °C Rain Wind (km/h) Gust Hum
06:00 6° dry 18 — 96%
07:00 7° dry 18 — 96.3%
08:00 7° 0.2mm 18 — 95.3%
09:00 7° 0.4mm 18 — 95%
10:00 7° 0.4mm 18 — 95.7%
11:00 7° dry 19 — 97.3%
12:00 8° dry 21 — 95.9%
13:00 9° 0.2mm 22 — 89%
14:00 9° 0.1mm 20 — 88.5%
15:00 9° dry 20 — 87.6%
16:00 8° dry 18 — 87.4%
17:00 7° dry 18 — 88.8%
18:00 7° dry 19 — 87.7%
19:00 7° dry 18 — 87.5%
20:00 6° dry 18 — 89.1%
21:00 6° dry 18 — 90.2%
Wed Wednesday 4 November
Caution
Temp8°C
Rain0.2mm
Wind27 km/h
Gusts—
Humidity74%
Should be drySandstone may still hold subsurface moisture
  • Hard sandstone climbs well when dry
  • Breezy — helps drying
Time °C Rain Wind (km/h) Gust Hum
06:00 6° dry 21 — 84.6%
12:00 8° dry 27 — 73.9%
18:00 7° dry 18 — 90.1%
Thu Thursday 5 November
Caution
Temp7°C
Rain0.1mm
Wind21 km/h
Gusts—
Humidity86%
Should be drySandstone may still hold subsurface moisture
  • Hard sandstone climbs well when dry
  • Breezy — helps drying
Time °C Rain Wind (km/h) Gust Hum
06:00 6° dry 17 — 89.6%
12:00 7° dry 21 — 86%
18:00 7° dry 14 — 82.9%
Fri Friday 6 November
Good
Temp8°C
Raindry
Wind18 km/h
Gusts—
Humidity81%
Should be dry
  • Hard sandstone climbs well when dry
Time °C Rain Wind (km/h) Gust Hum
06:00 5° dry 11 — 94.7%
12:00 8° dry 18 — 80.5%
18:00 7° dry 9 — 90.1%
Sat Saturday 7 November
Good
Temp8°C
Rain0.1mm
Wind14 km/h
Gusts—
Humidity88%
Should be dry
  • Hard sandstone climbs well when dry
Time °C Rain Wind (km/h) Gust Hum
06:00 6° 0.1mm 9 — 95.1%
12:00 8° dry 14 — 88%
18:00 6° dry 10 — 90.9%
Sun Sunday 8 November
Good
Temp7°C
Raindry
Wind8 km/h
Gusts—
Humidity82%
Should be dry
  • Hard sandstone climbs well when dry
Time °C Rain Wind (km/h) Gust Hum
06:00 5° dry 6 — 97.5%
12:00 7° dry 8 — 81.7%
18:00 6° dry 3 — 87.5%
Bird ban (1 March to 30 November)
Landowner permission granted only December 1st to February 28th; the cliff is an SSSI for rare plants and wildlife.

About Cwmyoy Boulders

Sandstone bouldering at the base of The Darren above the village of Cwmyoy in the Black Mountains. The cliff is a Site of Special Scientific Interest with rare plants, so cleaning must be kept to a minimum and nothing removed. Access is by the B4423 north from Llanfihangel Crucorney via Llanthony, or south from Hay-on-Wye over Gospel Pass.

Region
South Wales — Black Mountains
Rock type
Sandstone
Aspect
west-facing
Altitude
300m
Exposure
medium
Seepage
medium