Iceland Chmee2 · CC BY 3.0
The descent
The entrance, at 305 m.
The real relief above Grjótagjá, measured on the Copernicus model every 30 m, and the cave going down at the same vertical scale.
The depth is the one published by those who explored it; the shape of the galleries is a sketch, not a survey. No depth has been published for this cave yet.
305m
Entrance altitude
from the 30 m relief model
0°C
Inside, all year
the yearly average outside, at the entrance
113m
Rock above
the highest point within 1.5 km
Inside and outside
0 °C inside, all year.
Deep inside, a cave keeps the average temperature of the year outside: about 0 °C here, in January and in August. In July the afternoon reaches 10 °C at the entrance, 10 °C warmer than inside: take a jacket.
- -2°-8°Jan
- -2°-7°Feb
- -1°-7°Mar
- 1°-4°Apr
- 4°-1°May
- 8°3°Jun
- 10°5°Jul
- 9°4°Aug
- 6°2°Sep
- 2°-2°Oct
- -1°-6°Nov
- -2°-7°Dec
Outside: afternoon and night averages for 1991–2020 (NASA POWER) brought to the altitude of the entrance. Inside: the yearly average, which deep parts of a cave keep. Near the entrance it follows the weather a little.
Cave filled with hot water in Iceland
Grjótagjá is a cave in Iceland. The entrance is at 305 m. It has the shape of a lava tube.
Getting there.
- Wild cave: only with caving equipmentNo paths or lights inside. Go only with a caving club or a qualified guide.
- Akureyri International Airport (AEY)nearest airport with scheduled flights · 56 km in a straight lineCar hire at AEY airport (Akureyri)Discover Cars · sponsored link↗
Plan the visit
Guided tours, a bed nearby, a car.
Some links above are affiliate links: if you book through them we may earn a commission, at no extra cost to you. It never changes what the data on this page says.
From above.
The ground above the cave, with the relief shaded, the line of the section and what people have mapped around the entrance.
N
1.5 km
Sentinel-2 cloudless 2016 (EOX, CC BY 4.0), 6.0 × 6.0 km, north up. The line is the section above. Points © OpenStreetMap contributors.
Around the entrance.
- 1other cave entrances within 3 km
- 1marked hiking routes within 3 kmMellandahringur
- 1campsites within 8 kmVogar
- 11hotels and guesthouses within 8 kmSel, Skútustadir Guesthouse, Slow Travel Mývatn and 8 more
- springs within 2 km
- sinkholes within 3 km
- caving clubs and spots within 15 km
- viewpoints within 3 km
- climbing crags within 3 km
- named waterfalls within 4 km
- car parks within 2 km
- information boards and visitor centres within 3 km
- bus stops within 2 km
- restaurants and cafés within 3 km
Counted in OpenStreetMap, the map anyone can edit, around the entrance. A low number may just mean nobody has mapped it yet. © OpenStreetMap contributors (ODbL).
In our other atlases
What else is around Grjótagjá.
The river at the entrance, the waterfalls, the lakes, the mountains and volcanoes above, the canyons, beaches and islands nearby — from our other atlases.
Peakyas6 mountains within 10 kmFigures from the sister sites' databases (Wikidata, HydroATLAS, GeoNames, NOAA, OpenStreetMap). Links open when each site is online.
Month by month
The weather outside, at the entrance.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Afternoon | -2 | -2 | -1 | 1 | 4 | 8 | 10 | 9 | 6 | 2 | -1 | -2 |
| Afternoon | -2 | -2 | -1 | 1 | 4 | 8 | 10 | 9 | 6 | 2 | -1 | -2 |
| Night | -8 | -7 | -7 | -4 | -1 | 3 | 5 | 4 | 2 | -2 | -6 | -7 |
| Rain (mm) | 82 | 68 | 77 | 68 | 71 | 58 | 78 | 83 | 106 | 104 | 100 | 96 |
| Rainy days | 17 | 16 | 18 | 15 | 15 | 14 | 17 | 16 | 16 | 20 | 18 | 17 |
| Sun hours/day | 0.7 | 2.1 | 5.7 | 9.6 | 11.0 | 11.6 | 7.9 | 6.4 | 4.4 | 2.9 | 1.1 | 0.4 |
| Snow on the ground (cm) | 72 | 87 | 95 | 78 | 29 | 5 | 0 | 1 | 8 | 18 | 34 | 54 |
| Afternoon | Afternoon | Night | Rain (mm) | Sun hours/day | |
|---|---|---|---|---|---|
| Jan | -2 | -2 | -8 | 82 | 0.7 |
| Feb | -2 | -2 | -7 | 68 | 2.1 |
| Mar | -1 | -1 | -7 | 77 | 5.7 |
| Apr | 1 | 1 | -4 | 68 | 9.6 |
| May | 4 | 4 | -1 | 71 | 11.0 |
| Jun | 8 | 8 | 3 | 58 | 11.6 |
| Jul | 10 | 10 | 5 | 78 | 7.9 |
| Aug | 9 | 9 | 4 | 83 | 6.4 |
| Sep | 6 | 6 | 2 | 106 | 4.4 |
| Oct | 2 | 2 | -2 | 104 | 2.9 |
| Nov | -1 | -1 | -6 | 100 | 1.1 |
| Dec | -2 | -2 | -7 | 96 | 0.4 |
Averages 1991–2020 (NASA POWER) for a cell about 55 km wide, brought to the altitude of the entrance (305 m) with the standard lapse rate. Not a forecast.
Recent years
Wet years, dry years.
Rain of each month as a share of the 1991–2020 average. A dry year means a lower river and hotter rock; a wet one, more water in the gorge.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2020 | 121% | 144% | 94% | 99% | 53% | 74% | 120% | 84% | 125% | 97% | 110% | 159% |
| 2021 | 145% | 80% | 129% | 61% | 47% | 139% | 51% | 40% | 138% | 190% | 106% | 51% |
| 2022 | 64% | 123% | 65% | 75% | 160% | 195% | 120% | 159% | 66% | 163% | 93% | 81% |
| 2023 | 108% | 81% | 116% | 48% | 86% | 82% | 114% | 47% | 131% | 103% | 54% | 61% |
| 2024 | 53% | 91% | 139% | 105% | 48% | 190% | 90% | 185% | 73% | 104% | 65% | 47% |
| 2025 | 145% | 63% | 84% | 120% | 66% | 271% | 65% | 55% | 104% | 53% | 49% | 55% |
130% or more: wet month 70% or less: dry month
Caves nearby.
Grjótagjá
Iceland
- —Depth
- —Galleries
- 305 mEntrance altitude
- 0 °CInside, all year
Landmannahellir
Iceland · 201 km
- —Depth
- —Galleries
- 593 mEntrance altitude
- 0 °CInside, all year
Where these figures come from
| Name, type, published depth and length, visitors | Wikidata (Q966241) · CC0 |
|---|---|
| The relief above, the entrance altitude, the section and the 3D model | Copernicus DEM GLO-30 · © DLR e.V., © Airbus Defence and Space GmbH, Copernicus/ESA |
| Climate | NASA POWER, 1991–2020 |
| Entrances, springs, sinkholes, opening hours and what is around | © OpenStreetMap contributors · ODbL |
| Images | EOX Sentinel-2 cloudless 2016 · CC BY 4.0; Wikimedia Commons |
| Rivers, waterfalls, lakes, mountains, canyons, beaches and islands nearby | Coastya, Lakeyas, Peakyas, Cascadyas, Islandyas, Riveryas |
Every figure is an average, an estimate or a count from a public dataset. Licences and methods: data sources.
The family
Do you prefer beaches, lakes, mountains, waterfalls, islands, rivers, canyons, caves, dark skies, viewpoints, birdwatching or forests?
Same idea, other landscapes: field atlases built on open data, month by month, in seven languages.
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viewpoints
Every viewpoint with its real 360° panorama: the peaks you can name, how far you see and where the sun sets.Coming soonVisit 
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