Alps · Public domain · Wikimedia Commons
Mountain
Grand Cornier is a mountain in the Pennine Alps (Switzerland). Its summit stands 3,962 m above sea level. Its prominence — how far it rises above the highest saddle linking it to a taller summit — is 430 m.
From the lowest point within 5 km (1,928 m), it rises 2,034 m. The steepest side is the north-east face: 44° on average over the first kilometre. In places the ground near the top reaches 61° — terrain for climbers, not walkers.
The nearest town is Zermatt, 11 km away at 1,608 m: 2,354 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
9.3/10
Difficulty to the top
Alpine climb
Glaciers around the top.
Indicative only — never a safety assessment. Conditions change: ask local guides and check the forecast.
Ski score
9.4/10
Runs by difficulty
Snow season on the slopes (estimate)
Around 2,234 m, in the middle of the ski area: snow from November to May (some years from October to May).
51 lifts · lift stations from 1,700 to 2,769 m · 35 km cross-country
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 all year round. Month by month below, at different heights on the way up.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Summit3,962 msnow all year round | Snow on the ground all month | Snow on the ground all month | Snow on the ground all month | Snow on the ground all month | Snow on the ground all month | Snow on the ground all month | Snow on the ground all month | Snow on the ground all month | Snow on the ground all month | Snow on the ground all month | Snow on the ground all month | Snow on the ground all month |
Halfway up2,785 msnow from October to June | Snow on the ground all month | Snow on the ground all month | 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 | Snow on the ground all month | Snow on the ground all month | Snow on the ground all month |
Zermatt1,608 msnow from November 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 | Snow on the ground all month | Snow on the ground all month |
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 July afternoon the summit reaches about 4 °C; on January nights it falls to about -26 °C. In 9 months of the year it stays below freezing at the top even in the afternoon. In July the 0 °C line climbs to about 4,510 m, above the summit: the top thaws on an average afternoon. Across the region, February is the driest month (50 mm) and May the wettest (109 mm).
| Month | Summit high °C | Summit low °C | Zermatt high °C | 0 °C line (m) | Rain & snow (mm) | Wet days | Sun h/day |
|---|---|---|---|---|---|---|---|
| January | -17 | -26 | -2 | 1,370 | 63 | 11 | 3.3 |
| February | -16 | -26 | -1 | 1,470 | 50 | 10 | 4.5 |
| March | -13 | -22 | 2 | 1,940 | 63 | 12 | 5.5 |
| April | -8 | -16 | 7 | 2,700 | 70 | 14 | 6.3 |
| May | -3 | -12 | 12 | 3,510 | 109 | 18 | 6.6 |
| June | 2 | -8 | 17 | 4,250 | 97 | 17 | 8.5 |
| July | 4 | -6 | 19 | 4,510 | 96 | 16 | 8.8 |
| August | 3 | -6 | 18 | 4,450 | 99 | 15 | 7.9 |
| September | 0 | -10 | 15 | 3,880 | 68 | 14 | 6.9 |
| October | -5 | -13 | 10 | 3,200 | 72 | 13 | 5.0 |
| November | -11 | -19 | 4 | 2,200 | 91 | 14 | 3.1 |
| December | -16 | -24 | 0 | 1,530 | 68 | 12 | 2.6 |
Estimate: the NASA POWER climate of a ~55 km cell (average height 2,251 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. True scale: no vertical exaggeration.
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.
A lift reaches Hirli at 2,769 m — just 1,193 m below the summit.
Cabane de Bertol CAS (3,311 m), Col de la Dent Blanche CAS Bivouac (3,540 m), Cabane d'Arpitettaz (2,786 m), Cabane de Moiry (2,825 m) and 7 more
Furgg - Sandiger Boden, Matterhorn Express 2, Matterhorn Express 4, Matterhorn Express 3 and 1 more
Zermatt - Breuil-Cervinia, Zinal / Grimentz, Evolène, La Forclaz and 1 more
Edelweissweg, Matternhorn-Trail, Hobbit Trail, Pas du Chasseur and 28 more
Climbing, Sanieres, Hörnligrat and 2 more
Stockjigletscher, Tiefmattengletscher, Zmuttgletscher, Glacier du Grand Cornier and 31 more
Roc de la Vache and 6 more
Europe, Chalet Donadea, Auberge Les Bondes, Auberge La Navizence and 51 more
69 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 | -17 | -16 | -13 | -8 | -3 | 2 | 4 | 3 | 0 | -5 | -11 | -16 |
| 2020 | +2.3 | +3.1 | +0.5 | +2.0 | +2.1 | −1.8 | +1.0 | +0.8 | +1.1 | −2.4 | +3.5 | ±0.0 |
| 2021 | −1.7 | +2.9 | −0.3 | −0.5 | −2.5 | +1.0 | −0.2 | −0.4 | +1.6 | −0.3 | +0.3 | +1.5 |
| 2022 | +1.3 | +1.8 | +1.0 | +1.5 | +3.0 | +2.4 | +3.2 | +2.1 | −0.4 | +3.6 | +0.5 | +1.4 |
| 2023 | +0.3 | +2.2 | +2.1 | −0.3 | +0.4 | +0.7 | +1.3 | +0.9 | +4.1 | +2.4 | −0.9 | +2.2 |
| 2024 | +2.2 | +4.1 | +1.5 | −1.5 | −0.5 | −0.3 | +2.1 | +2.9 | −2.0 | +0.8 | +2.7 | +1.6 |
| 2025 | +2.1 | +2.6 | +1.2 | +2.3 | +0.7 | +4.0 | −0.7 | +1.4 | +0.5 | −0.4 | +0.3 | +2.5 |
+1 warmer than usual −1 cooler than usual
| Names, elevation, prominence | Wikidata (Q669875) · 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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