Right now

Temp16°C

Wind8 km/h

Gusts13 km/h

Humidity65.26%

Rain 48hdry

Last rainNone recent

Assessment

No recent rain

7-day forecast

Scroll through each day — hourly detail is shown inline.

Today Monday 28 September

Good

Temp16°C

Raindry

Wind10 km/h

Gusts13 km/h

Humidity60%

No recent rain

Good temperature for mountain rhyolite

Time °C Rain Wind (km/h) Gust Hum

15:00 16° dry 10 13 59.53%

18:00 16° dry 8 13 65.26%

21:00 15° dry 16 28 61.56%

Tue Tuesday 29 September

Poor

Temp18°C

Raindry

Wind37 km/h

Gusts61 km/h

Humidity78%

No recent rainWind 37 km/h, gusts 61 km/h — too windy

Very windy — consider sheltered alternatives

Time °C Rain Wind (km/h) Gust Hum

06:00 13° dry 21 40 84.1%

09:00 14° dry 31 53 83.97%

12:00 17° dry 38 61 80.35%

15:00 19° dry 36 57 76.22%

18:00 21° dry 34 56 71.15%

21:00 21° dry 37 59 72.86%

Wed Wednesday 30 September

Poor

Temp16°C

Rain14mm

Wind31 km/h

Gusts54 km/h

Humidity75%

14mm rain forecastWindy — 31 km/h, gusts 54 km/h

Good temperature for mountain rhyolite
Wet rhyolite is slippery; seepage from grass above can linger
Breezy — helps drying

Time °C Rain Wind (km/h) Gust Hum

06:00 15° 3mm 22 38 91.69%

09:00 15° 0.8mm 29 46 88.33%

12:00 16° dry 33 54 74.94%

15:00 16° dry 28 46 74.49%

18:00 15° 0.7mm 24 40 83.06%

21:00 14° 0.8mm 20 32 89.71%

Thu Thursday 1 October

Poor

Temp15°C

Rain3mm

Wind23 km/h

Gusts39 km/h

Humidity69%

3mm rain forecast

Good temperature for mountain rhyolite
Wet rhyolite is slippery; seepage from grass above can linger
Breezy — helps drying

Time °C Rain Wind (km/h) Gust Hum

06:00 12° 0.6mm 16 23 89.39%

09:00 13° 0.6mm 19 31 82.15%

12:00 14° 0.3mm 22 38 70.68%

15:00 15° dry 24 39 68.21%

18:00 14° dry 21 32 78.03%

21:00 14° dry 23 36 81.78%

Fri Friday 2 October

Poor

Temp15°C

Rain10mm

Wind23 km/h

Gusts38 km/h

Humidity82%

9.8mm rain forecast

Good temperature for mountain rhyolite
Wet rhyolite is slippery; seepage from grass above can linger
Breezy — helps drying

Time °C Rain Wind (km/h) Gust Hum

06:00 14° 3mm 24 37 93.34%

09:00 14° 3mm 21 34 90.87%

12:00 15° 1mm 23 38 81.54%

15:00 16° dry 23 38 81.73%

18:00 15° 0.4mm 18 27 91.1%

21:00 13° 0.7mm 16 24 94.77%

Sat Saturday 3 October

Poor

Temp15°C

Rain0.4mm

Wind17 km/h

Gusts29 km/h

Humidity80%

0.4mm rain forecast

Good temperature for mountain rhyolite

Time °C Rain Wind (km/h) Gust Hum

06:00 12° dry 13 20 96.18%

09:00 13° dry 14 22 90.94%

12:00 15° dry 17 29 80.89%

15:00 15° 0.4mm 17 28 79.88%

18:00 14° dry 13 19 91.39%

21:00 12° dry 13 19 94.28%

Sun Sunday 4 October

Caution

Temp15°C

Raindry

Wind12 km/h

Gusts22 km/h

Humidity78%

Should be dryHigh seepage — may still be weeping

Good temperature for mountain rhyolite

Time °C Rain Wind (km/h) Gust Hum

06:00 11° dry 12 17 95.94%

09:00 12° dry 12 18 88.67%

12:00 14° dry 12 22 78.09%

15:00 15° dry 12 21 77.81%

18:00 14° dry 10 14 90.57%

21:00 12° dry 9 13 94.29%

Mon Monday 5 October

Good

Temp15°C

Raindry

Wind12 km/h

Gusts22 km/h

Humidity77%

Should be dry

Good temperature for mountain rhyolite

Time °C Rain Wind (km/h) Gust Hum

06:00 10° dry 10 15 96%

09:00 12° dry 11 17 88.15%

12:00 14° dry 12 22 77.2%

15:00 16° dry 12 20 75.86%

About Cwm Silyn

Cwm Silyn consists of two impressive mountain buttresses, Craig yr Cwm Silyn, rising above a high corrie in the western Pennant hills. The rock is high-quality volcanic ash, offering clean slabs, sharp ribs, and featured crack lines on sound mountain rock. Facing northwest, the crag receives sun only in late afternoon, resulting in cold conditions and persistent dampness in sheltered cracks. Climbing centers on classic lower and middle-grade traditional multi-pitch routes, headlined by Kirkus' Route and Outside Edge. The approach demands a forty-five minute uphill walk across rough moorland and boulder fields from the Nantlle valley. Because of its remote, shaded mountain aspect, rapid weather changes and lingering dampness are the primary considerations.

Region: Snowdonia — Nantlle
Rock type: Rhyolite
Aspect: north-west-facing
Altitude: 550m
Exposure: high
Seepage: high

Other crags in this region

Craig y Bera