Iceland Lava tube
Víðgelmir
2 °C inside, all year.
Olikristinn · CC BY-SA 3.0
The descent
The entrance, at 234 m.
The real relief above Víðgelmir, 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.
234m
Entrance altitude
from the 30 m relief model
2°C
Inside, all year
the yearly average outside, at the entrance
144m
Rock above
the highest point within 1.5 km
Inside and outside
2 °C inside, all year.
Deep inside, a cave keeps the average temperature of the year outside: about 2 °C here, in January and in August. In July the afternoon reaches 13 °C at the entrance, 11 °C warmer than inside: take a jacket.
- -1°-6°Jan
- -1°-6°Feb
- 0°-5°Mar
- 4°-2°Apr
- 7°1°May
- 11°5°Jun
- 13°7°Jul
- 12°6°Aug
- 8°3°Sep
- 4°-1°Oct
- 0°-4°Nov
- -1°-6°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.
Lava tube in Iceland
Víðgelmir is a lava tube in Iceland. The entrance is at 234 m. It has an underground river and 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.
- Reykjavík Domestic Airport (RKV)nearest airport with scheduled flights · 88 km in a straight lineCar hire at RKV airport (Reykjavík)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.
The water
The Norðlingafljót runs highest from April to July and from December to February.
The Norðlingafljót carries about 35 m³/s on average here. It runs highest from April to July and from December to February, fed by melting snow.
- 32 m³/sJan
- 31 m³/sFeb
- 28 m³/sMar
- 34 m³/sApr
- 42 m³/sMay
- 55 m³/sJun
- 33 m³/sJul
- 15 m³/sAug
- 30 m³/sSep
- 27 m³/sOct
- 26 m³/sNov
- 34 m³/sDec
From about 15 m³/s in the lowest month to 55 m³/s in the highest. Its basin above this point covers 1,089 km².
The Hvítá from source to mouth on Riveryas — coming soon
Estimate: long-term flow from the HydroATLAS model (WaterGAP, 1971–2000) shaped by the monthly rain, snow and temperature of the area (NASA POWER). Dams change it. Not a forecast.
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 kmVíðgelmir
- 1named waterfalls within 4 kmVeitufoss
- 1car parks within 2 km
- 1information boards and visitor centres within 3 km
- 2campsites within 8 kmHúsafell
- 3hotels and guesthouses within 8 kmGuesthouse Gamli Bær, Hótel Húsafell
- springs within 2 km
- sinkholes within 3 km
- caving clubs and spots within 15 km
- viewpoints within 3 km
- marked hiking routes within 3 km
- climbing crags 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 Víðgelmir.
The river at the entrance, the waterfalls, the lakes, the mountains and volcanoes above, the canyons, beaches and islands nearby — from our other atlases.
Riveryas1 rivers at the entrance
Lakeyas1 lakes within 10 km
Peakyas2 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 | -1 | -1 | 0 | 4 | 7 | 11 | 13 | 12 | 8 | 4 | 0 | -1 |
| Afternoon | -1 | -1 | 0 | 4 | 7 | 11 | 13 | 12 | 8 | 4 | 0 | -1 |
| Night | -6 | -6 | -5 | -2 | 1 | 5 | 7 | 6 | 3 | -1 | -4 | -6 |
| Rain (mm) | 181 | 166 | 160 | 128 | 98 | 88 | 109 | 115 | 176 | 144 | 148 | 181 |
| Rainy days | 22 | 20 | 22 | 18 | 18 | 17 | 19 | 20 | 21 | 20 | 20 | 21 |
| Sun hours/day | 0.3 | 1.0 | 4.0 | 6.9 | 8.2 | 8.2 | 6.9 | 5.9 | 3.6 | 2.2 | 0.5 | 0.4 |
| Snow on the ground (cm) | 62 | 76 | 88 | 81 | 54 | 11 | 1 | 1 | 5 | 14 | 25 | 41 |
| Afternoon | Afternoon | Night | Rain (mm) | Sun hours/day | |
|---|---|---|---|---|---|
| Jan | -1 | -1 | -6 | 181 | 0.3 |
| Feb | -1 | -1 | -6 | 166 | 1.0 |
| Mar | 0 | 0 | -5 | 160 | 4.0 |
| Apr | 4 | 4 | -2 | 128 | 6.9 |
| May | 7 | 7 | 1 | 98 | 8.2 |
| Jun | 11 | 11 | 5 | 88 | 8.2 |
| Jul | 13 | 13 | 7 | 109 | 6.9 |
| Aug | 12 | 12 | 6 | 115 | 5.9 |
| Sep | 8 | 8 | 3 | 176 | 3.6 |
| Oct | 4 | 4 | -1 | 144 | 2.2 |
| Nov | 0 | 0 | -4 | 148 | 0.5 |
| Dec | -1 | -1 | -6 | 181 | 0.4 |
Averages 1991–2020 (NASA POWER) for a cell about 55 km wide, brought to the altitude of the entrance (234 m) with the standard lapse rate. Not a forecast.
Photographs
Inside and around.
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 | 152% | 81% | 103% | 110% | 117% | 124% | 80% | 144% | 129% | 54% | 105% | 72% |
| 2021 | 62% | 60% | 116% | 94% | 47% | 131% | 100% | 94% | 137% | 102% | 146% | 72% |
| 2022 | 159% | 72% | 181% | 66% | 120% | 135% | 126% | 127% | 70% | 77% | 40% | 34% |
| 2023 | 90% | 163% | 31% | 71% | 249% | 154% | 26% | 72% | 94% | 94% | 60% | 82% |
| 2024 | 91% | 71% | 55% | 64% | 134% | 131% | 126% | 105% | 69% | 122% | 126% | 132% |
| 2025 | 93% | 125% | 134% | 66% | 112% | 120% | 129% | 89% | 98% | 101% | 30% | 72% |
130% or more: wet month 70% or less: dry month
Caves nearby.
Víðgelmir
Iceland
- —Depth
- —Galleries
- 234 mEntrance altitude
- 2 °CInside, all year
Raufarhólshellir
Iceland · 95 km
- —Depth
- —Galleries
- 167 mEntrance altitude
- 4 °CInside, all year
Where these figures come from
| Name, type, published depth and length, visitors | Wikidata (Q626642) · 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 |
| River flow and basin | HydroATLAS / RiverATLAS v1.0 (Linke et al. 2019) · CC BY 4.0 |
| 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.
beaches
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Every summit in 3D: summit weather, the 0 °C line, huts and trails.Visit 
waterfalls
Every waterfall: height, flow month by month and when it roars.Visit 
islands
Every island from the sea up: size, sea temperature, ferries and 3D.Visit rivers
Every river from source to sea: the journey, the flow and the basin in numbers.Visit 
canyons
Every canyon cut to scale: depth to the floor, rim and floor temperatures, trails and viewpoints.Visit 
caves
Every cave with its real depth and length: the rock above, the temperature inside all year, and how to visit.You are here
dark skies
Where the night is still dark: the sky of every place, the Milky Way month by month, the Moon, eclipses and auroras.Coming soonVisit 
viewpoints
Every viewpoint with its real 360° panorama: the peaks you can name, how far you see and where the sun sets.Coming soonVisit 
birdwatching
Every bird sanctuary and wetland with the species recorded month by month: who is resident, who comes for the summer, who only passes through.Coming soonVisit 
forests
Every forest with its land-cover rings, what grows and lives in it, and the best months to walk it.Coming soonVisit