3D view drawn from Copernicus WorldDEM-30 (© DLR e.V., © Airbus Defence and Space GmbH, Copernicus/ESA) and Sentinel-2 cloudless 2016 by EOX IT Services GmbH, CC BY 4.0
Highest mountain in Wales
Snowdon is a mountain in the Snowdonia (United Kingdom). Its summit stands 1,085 m above sea level. Its prominence — how far it rises above the highest saddle linking it to a taller summit — is 1,039 m, and the nearest higher ground is 369 km away. It was first climbed in 1639.
From the lowest point within 5 km (52 m), it rises 1,033 m. The steepest side is the south face: 30° on average over the first kilometre. In places the ground near the top reaches 55° — terrain for climbers, not walkers.
The nearest town is Llanberis, 6 km away at 128 m: 957 m below the summit.
Scores
Two scores out of 10, built only from open data — every part is shown. They describe what the mountain offers, not how safe it is.
Hiking & mountaineering
8.0/10
Difficulty to the top
Mountain walk
Most path sections around the top are T3 on the SAC hiking scale.
Indicative only — never a safety assessment. Conditions change: ask local guides and check the forecast.
Ski score
—
No ski runs within 12 km in OpenStreetMap.
Ski (where OpenStreetMap has skiing within 12 km): up to 4 points for the length of downhill runs (300 km or more = 4), 1.5 for the number of lifts (40+), 1.5 for the vertical between lift stations (1,500 m) and 3 for the snow season — a month counts when the estimated mean temperature at the height of the ski area is −1 °C or lower and snow falls or lies there (NASA POWER, 2001–2020). Hiking & mountaineering: up to 2.5 for waymarked routes and paths, 1.5 for huts, 2 for the ascent from the valley (2,000 m), 1.5 for prominence (3,000 m), 1.5 for the season (months with summit afternoons above −5 °C) and 1 for via ferratas, climbing and glaciers. OpenStreetMap is built by volunteers: where few things are mapped, a score can be lower than reality.
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Snow
At the summit, snow from December to April. Month by month below, at different heights on the way up.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Summit1,085 msnow from December to April | Snow on the ground all month | Snow on the ground all month | Snow on the ground all month | Snow on the ground all month | No snow | No snow | No snow | No snow | No snow | No snow | No snow | Snow on the ground all month |
Halfway up606 mno snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow |
Llanberis128 mno snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow | No snow |
Estimate for a normal year: average temperature and precipitation from NASA POWER, carried to each height, in a simple model of snow building up and melting. In a given year snow can come earlier or stay longer. It does not replace the local snow and avalanche bulletin.
Summit weather
Not a forecast: long-term averages (1991–2020), carried up to the summit. The orange line is where an average afternoon reaches 0 °C; above the dashed blue line it freezes even at dawn.
On an average August afternoon the summit reaches about 10 °C; on February nights it falls to about -2 °C. Afternoons at the top are above freezing in every month of the average year. In August the 0 °C line climbs to about 2,700 m, above the summit: the top thaws on an average afternoon. Across the region, April is the driest month (70 mm) and December the wettest (147 mm).
| Month | Summit high °C | Summit low °C | Llanberis high °C | 0 °C line (m) | Rain & snow (mm) | Wet days | Sun h/day |
|---|---|---|---|---|---|---|---|
| January | 1 | -2 | 7 | 1,240 | 123 | 19 | 1.2 |
| February | 1 | -2 | 7 | 1,190 | 101 | 16 | 2.6 |
| March | 2 | -2 | 8 | 1,350 | 90 | 16 | 4.5 |
| April | 4 | 0 | 10 | 1,680 | 70 | 15 | 6.4 |
| May | 7 | 3 | 13 | 2,100 | 75 | 14 | 7.7 |
| June | 9 | 5 | 15 | 2,470 | 84 | 15 | 7.5 |
| July | 10 | 7 | 17 | 2,680 | 96 | 17 | 6.7 |
| August | 10 | 7 | 17 | 2,700 | 108 | 19 | 6.0 |
| September | 9 | 6 | 16 | 2,530 | 103 | 16 | 4.9 |
| October | 7 | 4 | 13 | 2,150 | 132 | 19 | 2.9 |
| November | 4 | 2 | 10 | 1,700 | 142 | 21 | 1.5 |
| December | 2 | 0 | 8 | 1,390 | 147 | 20 | 0.8 |
Estimate: the NASA POWER climate of a ~55 km cell (average height 68 m), adjusted to the summit by −6.5 °C per 1,000 m. Rain, wet days and sunshine are those of the region. Mountain weather changes fast — always check a local forecast. ★ = mildest months at the top.
Relief
Two cuts through the summit, 16 km long, from the 30 m Copernicus elevation model. Heights drawn 2× taller than lengths, so the shape can be seen.
Average slope of the first kilometre from the summit. The orange petal is the steepest side.
Around the mountain
Counted around the summit in OpenStreetMap, the map anyone can edit. The satellite plate shows 14 × 14 km.
N
5 km
Sentinel-2 cloudless 2016 (EOX, CC BY 4.0), 14 × 14 km, north up. Points © OpenStreetMap contributors.
ULMC Caseg Fraith Hut, Lletty Llwyd, Cwm Glas Mawr, Ynys Ettws and 9 more
Vivian Incline
Welsh Three Thousands, Lôn Gwyrfai, Llwybr Llyn Llydaw, Llanberis Path and 12 more
Clogwyn Du'r Arddu West Buttress, Dinas Mot, Dali's Hole, Australia and 7 more
Clogwyn y Fulfran, Eagles Rock, Twll Du, Rhaeadr Llanberis and 19 more
Llwyn Celyn bach, Llanberis Touring Park, Cwellyn Arms Campsite, Bryn Gloch and 14 more
Seiont Manor, Dolbadarn Hotel, The Heights, Snowdonia Mountain Lodge and 72 more
106 path sections within 5 km, by SAC hiking scale (T1 easy walk … T6 difficult alpine).
OpenStreetMap is built by volunteers: a low number may just mean nobody has mapped it yet. Places © OpenStreetMap contributors (ODbL).
Photos
Recent years
Afternoon high at the summit (estimate). The first row is the reference, the 1991–2020 average in °C; the years show only the difference.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1991–2020 average | 1 | 1 | 2 | 4 | 7 | 9 | 10 | 10 | 9 | 7 | 4 | 2 |
| 2020 | +1.1 | +1.0 | +0.3 | +2.1 | +1.1 | +0.6 | −1.0 | +1.0 | ±0.0 | −0.8 | +0.8 | −0.2 |
| 2021 | −1.0 | −0.1 | +0.5 | −0.9 | −1.4 | +0.3 | +1.7 | +0.3 | +1.6 | +0.7 | +0.4 | +0.5 |
| 2022 | +0.8 | +1.7 | +1.8 | +0.6 | +0.5 | +0.3 | +1.2 | +2.4 | +0.8 | +1.5 | +1.4 | −0.9 |
| 2023 | +0.7 | +1.3 | ±0.0 | +0.4 | +1.2 | +3.3 | −0.1 | +0.2 | +2.2 | +0.7 | +0.2 | +1.0 |
| 2024 | +0.1 | +1.7 | +0.9 | +0.3 | +1.7 | −0.8 | −0.3 | +0.5 | ±0.0 | +0.4 | +0.5 | +0.9 |
| 2025 | −0.4 | +0.1 | +1.7 | +2.6 | +2.0 | +1.1 | +1.3 | +1.9 | +0.1 | +0.3 | +0.7 | +0.7 |
+1 warmer than usual −1 cooler than usual
| Names, elevation, prominence | Wikidata (Q217142) · CC0 |
|---|---|
| Relief, 3D view, profiles | Copernicus DEM GLO-30 · © DLR e.V., © Airbus Defence and Space GmbH, Copernicus/ESA |
| Climate | NASA POWER, 1991–2020 · CC BY 4.0 |
| Around the mountain | © OpenStreetMap contributors · ODbL |
| Images | EOX Sentinel-2 cloudless 2016 · CC BY 4.0; Wikimedia Commons |
Every figure is an average, an estimate or a count from a public dataset. Licences and methods: data sources.
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