Snowdonia is one of the wettest places in Britain, and the summit is much colder and windier than the valleys. Long days in late spring and summer give the most time for walks.
Season by season
Spring (March–May)
Lambs in the fields, snow lingering on the tops into April, and often some of the driest weeks of the year in May.
Summer (June–August)
The busiest time: long days, all railways and buses running, full car parks. Start early.
Autumn (September–November)
Golden bracken and woodland around Betws-y-Coed. Quieter paths, but more rain and shorter days.
Winter (December–February)
Snow and ice on the summits; the railway does not run to the top. Low-level walks and castles are still rewarding.
Month by month
| Month | Avg high / low | Wet days | Daylight | Our verdict |
|---|---|---|---|---|
| January | 7° / 1°C | ≈19 | ≈8.5 h | Quiet & cheap |
| February | 7° / 1°C | ≈15 | ≈10 h | Quiet & cheap |
| March | 9° / 2°C | ≈16 | ≈11.8 h | Good |
| April | 12° / 4°C | ≈13 | ≈13.7 h | Good |
| May | 15° / 6°C | ≈13 | ≈15.3 h | Best |
| June | 18° / 9°C | ≈12 | ≈16.2 h | Best |
| July | 19° / 11°C | ≈13 | ≈15.7 h | Peak season |
| August | 19° / 11°C | ≈15 | ≈14.3 h | Peak season |
| September | 17° / 9°C | ≈15 | ≈12.5 h | Best |
| October | 13° / 7°C | ≈18 | ≈10.7 h | Good |
| November | 10° / 4°C | ≈19 | ≈9 h | Quiet & cheap |
| December | 8° / 2°C | ≈19 | ≈8.1 h | Quiet & cheap |
Approximate long-term averages, rounded; daylight is the approximate time between sunrise and sunset mid-month. Wales is mild but wet, and the mountains are colder, windier and wetter than the coast: pack layers in every season.
Festivals & events
- Summer Mountain running and walking festivals in Llanberis and around the park.
- August (some years) The National Eisteddfod of Wales visits the north in some years; check where it is held.
Crowds & booking ahead
Weekends and school holidays bring queues at Pen-y-Pass and on the summit. Walk midweek, start early, and book railway tickets well ahead.
