Llanberis has about 17 hours of daylight in mid-June and about 7.5 hours in mid-December.
For the best odds on Snowdon (Yr Wyddfa), look at a weekday in May or June. The days are long, the summit café is open, and the valley records its driest months.
Walker counts in those two months sit well below August.
No month promises a clear summit. The forecast a few hours before you start counts for more than the calendar.
Daylight and the year in one table
Daylight sets the first limit. The sunrise and sunset tables on timeanddate.com give 16 h 56 min of daylight in Llanberis on 15 June 2026.
For 15 December the figure is 7 h 35 min.
On the 15th, daylight runs from 7 h 35 min in December to 16 h 56 min in June.
Sunrise is 4:49 am in mid-June and 8:24 am in mid-December. A start timed for sunrise is a different plan in each of those months.
Train dates below are the Snowdon Mountain Railway’s 2026 season; café dates are from its visitor information. Walker counts are from the 2022 report of the Eryri National Park Authority, which counts walkers on the paths of Yr Wyddfa.
| Month | Daylight, 15th | What changes |
|---|---|---|
| January | 8 h 07 min | Park winter reports, twice a week |
| February | 9 h 54 min | Park winter reports, twice a week |
| March | 11 h 49 min | Clogwyn trains from 28 March |
| April | 13 h 59 min | Clogwyn trains only, to 30 April |
| May | 15 h 51 min | Summit trains and café from 1 May |
| June | 16 h 56 min | Driest at Capel Curig, with May |
| July | 16 h 27 min | 79,677 walkers in 2022 |
| August | 14 h 47 min | 102,437 walkers in 2022, the most |
| September | 12 h 42 min | 55,103 walkers in 2022 |
| October | 10 h 38 min | Café open to 25 October |
| November | 8 h 40 min | Last diesel train 1 November |
| December | 7 h 35 min | 9,136 walkers in 2022, the fewest |
When the railway and summit café run
The railway’s diesel trains ran to Clogwyn Station, three-quarters of the way up, from 28 March to 30 April 2026. They run to the summit from 1 May to 25 October.
Hafod Eryri is the summit visitor centre and café. It opens from 10 am daily from 1 May to 25 October, weather permitting.
It stays closed on bad-weather days and whenever the train cannot reach the summit, according to the railway’s visitor information.
Read on 20 October 2026, the same information gives these end-of-season dates:
- Summit trains run from 19 to 25 October.
- Trains go to Clogwyn Station only from 26 October to 1 November.
- The last diesel service is 1 November 2026.
- The final steam service is 30 October 2026.
From 5 October, selected services have run to Clogwyn Station only, because of essential works.
High winds can affect services year-round. Hikers should be prepared to walk back down if required.
The railway had published no 2027 season dates when read on 20 October 2026.
When winter conditions come
The Park’s winter ground-condition reports on Yr Wyddfa run twice a week from November until March. The Park announced that service in 2022.
Its current ground conditions page says reports are published every Tuesday and Friday, now on the Yr Wyddfa Live website. It warns that conditions in late autumn and winter can be treacherous.
The Park gives no start or end date for winter conditions.
On its climbing page the Park says snow can cover much of the summit during the winter.
It is impossible to reach the summit in winter conditions without specialised equipment such as crampons or ice axes and knowing how to use them.
The railway says ice or snow can keep trains below the summit in early spring. In 2026 the trains ran only to Clogwyn Station until 30 April.
What the reports say, and the kit that winter needs, is set out for Snowdon in winter.
The busiest months and days
In 2022 the Authority’s counters recorded 543,541 walkers on the six main paths, counted one way. August was the busiest month, with 102,437. December was the quietest, with 9,136.
May and June recorded 64,164 and 65,322. Some 2019 data was extrapolated to fill gaps in the 2022 counts.
Saturday was far ahead of every other day, with 173,375 walkers. Sunday followed with 103,892.
Each weekday carried between 49,485 and 55,864.
The Park’s 2025 report shows the same pattern on the five paths it counted, with August and Saturday highest on each. Llanberis data was unavailable for 2025.
The Park also says the summit can get very busy during the summer season. During spring and summer its car parks at Llanberis, Pen-y-Pass, Nant Peris and Pont Bethania are very busy.
In 2023 the Authority said that bank holidays in Eryri can be extremely busy.
Saturday leads the counters, and bank holidays and summer are the Park’s busy times. How the crowds spread across the paths is covered in how busy Snowdon gets.
Pen-y-Pass parking
The Park says that between March and November, planning how to get to Pen-y-Pass in advance is essential.
Read on 20 October 2026, pre-booking is open through JustPark. It remains on a pre-booking system until 1 November 2026.
Extensions to existing bookings are not possible, because parking is very limited.
The Pen-y-Pass start point has the routes that leave from there.
What the valley averages show
The Met Office, the UK’s national weather service, keeps climate averages for Capel Curig No 3, a valley station. Its figures cover 1991 to 2020 and describe the valley, not the summit.
- Driest months: May with 142 mm of rain and June with 144 mm.
- Wettest month: December with 346 mm, ahead of January with 310 mm.
- Air frost: 8.5 days in January, 0.03 in June, none in July or August.
The Park says it is much colder, wetter and windier at the summit of Yr Wyddfa. Read these as valley figures; the summit is colder and wetter.
The forecast matters more than the month
The Park’s safety advice is plain: the best time to check the forecast is a few hours before the start of your journey. Forecasts are more accurate then, and the Met Office service carries the latest.
The Park also says weather in upland areas can change within hours. On Yr Wyddfa it can change within minutes.
If the weather conditions start to get too much for your ability, you should turn back immediately.
We compile and explain public route and safety information. We guide nobody and sell nothing on the hill.
Once you have chosen a month, reading the mountain forecast is how you choose the day.
