Roger McLassus · CC BY-SA 3.0 · Wikimedia Commons
Volcano in Iceland
Grímsvötn is a volcano in Iceland. Its summit stands 1,725 m above sea level.
From the lowest point within 5 km (1,334 m), it rises 391 m. The steepest side is the east face: 18° on average over the first kilometre. In places the ground near the top reaches 53° — terrain for climbers, not walkers.
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
2.9/10
Difficulty to the top
Alpine climb
Estimated from the slope: OpenStreetMap has no graded paths near the top.
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.
Plan your visit
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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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Summit1,725 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 |
Foot of the mountain1,334 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 |
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 -2 °C; on February nights it falls to about -15 °C. Even in the warmest month the summit stays below freezing all day: ice and snow all year round. Even at its highest, in July, the 0 °C line reaches only about 1,440 m: 285 m below the summit. Across the region, June is the driest month (116 mm) and January the wettest (327 mm).
| Month | Summit high °C | Summit low °C | 0 °C line (m) | Rain & snow (mm) | Wet days | Sun h/day |
|---|---|---|---|---|---|---|
| January | -10 | -15 | 240 | 327 | 28 | 1.0 |
| February | -10 | -15 | 230 | 298 | 24 | 3.5 |
| March | -9 | -14 | 270 | 269 | 26 | 7.8 |
| April | -7 | -12 | 630 | 219 | 23 | 12.1 |
| May | -5 | -9 | 950 | 144 | 21 | 14.5 |
| June | -3 | -5 | 1,320 | 116 | 20 | 14.0 |
| July | -2 | -4 | 1,440 | 144 | 23 | 11.2 |
| August | -2 | -4 | 1,430 | 171 | 23 | 9.3 |
| September | -3 | -6 | 1,260 | 284 | 25 | 6.2 |
| October | -6 | -10 | 800 | 273 | 26 | 4.3 |
| November | -8 | -13 | 430 | 268 | 25 | 1.8 |
| December | -10 | -15 | 260 | 322 | 26 | 0.6 |
Estimate: the NASA POWER climate of a ~55 km cell (average height 1,135 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 6× 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.
Grímsfjall (1,722 m)
OpenStreetMap is built by volunteers: a low number may just mean nobody has mapped it yet. Places © OpenStreetMap contributors (ODbL).
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 | -10 | -10 | -9 | -7 | -5 | -3 | -2 | -2 | -3 | -6 | -8 | -10 |
| 2020 | −0.2 | −1.0 | −1.2 | +0.3 | +0.1 | +0.2 | −0.5 | +0.7 | −0.3 | +0.4 | −0.3 | −1.3 |
| 2021 | −2.9 | +0.6 | +0.8 | −1.1 | −2.6 | −0.4 | +1.2 | +1.3 | +0.1 | +0.5 | −0.1 | −0.2 |
| 2022 | +0.6 | −2.9 | +2.6 | +1.3 | +1.1 | +0.1 | −0.1 | −0.2 | +1.0 | −0.3 | +2.6 | −6.1 |
| 2023 | −1.9 | +1.8 | −5.0 | +1.0 | +1.5 | +1.2 | −0.4 | +0.4 | ±0.0 | −0.9 | +0.3 | −3.1 |
| 2024 | −1.2 | −2.0 | −0.6 | −1.5 | +1.6 | −0.6 | +0.1 | −0.5 | −1.1 | −1.1 | −0.1 | −1.0 |
| 2025 | −1.5 | +2.7 | +1.5 | +1.4 | +2.8 | −0.8 | +1.0 | +1.0 | +0.5 | −0.2 | −1.9 | +2.3 |
+1 warmer than usual −1 cooler than usual
| Names, elevation, prominence | Wikidata (Q182913) · 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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