Guide · Season

Iceland ice caves in winter, month by month

Natural ice caves form in the melt of summer and open once frost returns. Here is when the season runs at the lagoon, what each winter month feels like, and what is left if you come in summer.

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Editorial team, blue-ice-cave-iceland.comUpdated October 25, 20266 minutes to read25 sources

Bookable here: the tour Blue ice cave tour from Jökulsárlón 4.6 (961 reviews) 3 hoursSmall group, up to 14Helmets and crampons included from$195per person Check availabilityFree cancellation up to 24 hrs before

Season at a glance

01Lagoon caves: Ice Explorers runs its cave tour from October to April.¹
02Typical season: Visit Iceland gives November through May, varying with the weather.²
03Why winter: Meltwater carves the tunnels in spring and summer; frost makes them ready to explore.³
04Darkest month: In December the sun is up about 4.3 hours at the lagoon's latitude.⁴
05In summer: The Katla cave and the Langjökull tunnel are listed as open all year.⁵ ⁶

Why natural ice caves are a winter thing

Iceland ice caves in winter are not a marketing season but a physical one. Visit Iceland explains that in spring and summer meltwater usually forms the caves as outflow tunnels, and that in the fall, once temperatures have dropped below freezing again, they are ready for exploration until the next spring.³ The same water that carves a cave makes it dangerous while it is still running.

NSIDC, the US snow and ice data center, describes glacier caves as carved out by water running through or under the ice.⁷ The US National Park Service warns, for its own glaciers, that ice caves and meltwater channels are prone to spontaneous collapse because of melting, and that meltwater volumes inside increase throughout the day in the warm season.⁸ ⁹

That is why the lagoon operators switch products with the seasons. Ice Explorers runs its natural ice cave tour from October to April and offers a glacier walk from May to September instead.¹ ¹⁰ The cave tour this site sells belongs to that winter window; outside it, you walk on the same glacier rather than into it.

The ice cave year

How a season unfolds at the lagoon

Spring and summer

Meltwater carves tunnels

Outflow tunnels form under and through the ice.³
May to September

Glacier walks

Ice Explorers runs walks on the ice instead of cave tours.¹⁰
October

Cave tours begin

The first month of Ice Explorers' cave season.¹
November

Typical season start

Visit Iceland's usual start of the ice cave season.²
December

Shortest days

About 4.3 hours of sun at mid-month.⁴
April to May

The season closes

Ice Explorers ends in April; Visit Iceland gives May.¹ ²

When the season starts and ends

There is no fixed opening day. Visit Iceland says the ice cave season varies with temperatures and weather conditions but typically extends from November through May.² Ice Explorers lists October to April for both its short cave tour and its longer exploration tour, which shows how operators read the same ice slightly differently.¹ ¹¹

Each new season brings new caves. Ice Explorers says that from season to season, and even within a season, the caves change, with old ones disappearing and new ones forming.¹² Guides look for the caves that are safe and accessible each year, so the first weeks of a season can look quite different from the last.

The practical rule is simple: the months inside both definitions, November to April, are the most dependable on paper, while October and May depend more on the year.² ¹ Book early-season or late-season dates with free cancellation, and read the operator's own updates rather than old photos.

Month by month

Darkness at the lagoon through the year

Hours without sunDays with precipitationSeason

Columns give the hours without daylight on the 15th of each month, calculated for the lagoon's latitude. The station behind the temperatures, Icelandic Meteorological Office Fagurhólsmýri, about 30 km south-west of the lagoon, published no count of wet days, so none is drawn.⁴

Station averages

Daylight, highs and lows near Jökulsárlón

Month	Daylight (h)	Darkness (h)	High / low	Wet days	Ice Explorers runs
Jan	5.4	18.6	4 / -2 °C	-	Ice cave tours
Feb	8.5	15.5	4 / -2 °C	-	Ice cave tours
Mar	11.6	12.4	4 / -1 °C	-	Ice cave tours
Apr	15	9	7 / 1 °C	-	Ice cave tours
May	18.2	5.8	10 / 4 °C	-	Glacier walks
Jun	20.9	3.1	12 / 7 °C	-	Glacier walks
Jul	19.8	4.2	14 / 8 °C	-	Glacier walks
Aug	16.5	7.5	14 / 8 °C	-	Glacier walks
Sep	13.2	10.8	11 / 6 °C	-	Glacier walks
Oct	10	14	8 / 3 °C	-	Ice cave tours
Nov	6.6	17.4	5 / 0 °C	-	Ice cave tours
Dec	4.3	19.7	4 / -1 °C	-	Ice cave tours

Daylight is calculated for mid-month at the lagoon; highs and lows are monthly means of the Icelandic Meteorological Office station Fagurhólsmýri, about 30 km south-west of the lagoon, 1991 to 2008; the station published no count of wet days.⁴ Season according to Ice Explorers.¹

Parts of the season

Early, deep or late winter

Fresh caves

Early winter

October to December

Wettest month: October
Daylight mid-December: 4.3 hours
Season status: Opening

Check dates

Steady frost

Deep winter

January and February

January low: -1.9 °C
Daylight mid-February: 8.5 hours
Season status: Core season

Check dates

Longer days

Late winter

March and April

Daylight mid-March: 11.6 hours
April high: 7 °C
Season status: Closing

Check dates

Decision helper

Which month for your trip?

Pick what matters most to you

I want the best odds of a natural cave I want more daylight for driving I can only travel in July I want the winter atmosphere at its deepest I travel in May

January or February

Both sit inside Visit Iceland's and Ice Explorers' seasons.² ¹

March

The sun is up about 11.6 hours at mid-month.⁴

Katla or the tunnel

Both are listed as open all year.⁵ ⁶

December

Daylight is down to about 4.3 hours.⁴

Ask before booking

May falls in Visit Iceland's season but outside Ice Explorers' cave months.² ¹⁰

In spring and summer, meltwater usually forms them as outflow tunnels. In the fall, when temperatures have gone below freezing again, they are ready for exploration until next spring.

Visit Iceland (Business Iceland)Source 3

What each winter month feels like

Winter near the lagoon is wet and dark rather than bitterly cold. At the Met Office station Fagurhólsmýri, between Skaftafell and the lagoon, January averages a daily high of 3.9 °C and a low of -1.9 °C, with 171 mm of precipitation in the month.⁴ February is slightly colder at night, averaging -2.1 °C.⁴

Daylight is the bigger factor. At the lagoon's latitude the sun is up about 4.3 hours at mid-December, 5.4 hours at mid-January and 8.5 hours at mid-February, before March climbs to 11.6 hours.⁴ Short days mean morning tours start in low light and the drive back often happens in the dark.

Rain and snow are part of the deal in every month. October is the wettest month in the station record, with 197 mm, and September follows with 190 mm.⁴ Safetravel calls the weather the biggest concern when outdoors in Iceland, warning that cold, strong wind and rain together can be fatal without the right clothing and equipment.¹³

Checklist

Planning around the season

Before you book

Check the operator's season months
Choose free cancellation
Look up daylight for your dates

Winter travel

Wool and synthetic layers, no cotton
Winter tires and crampons for walks
A spare day for weather

Calculator

Price a winter cave tour

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Lagoon blue ice caveOctober to Aprilfrom $195 Cave & glacier dayLonger lagoon tourfrom $275 Katla ice caveListed all yearfrom $194

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Total from$390

per participant from $195

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We take the cheapest GetYourGuide price of the ice cave tour you choose, multiply it by your group and convert it with the ECB daily rate; checkout on GetYourGuide has the final figure.

Video

A January ice cave tour on Vatnajökull from the lagoon

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An ice cave in December, February or March?

Visiting an ice cave in December gives you the full winter mood and the shortest days of the year, with about 4.3 hours of sun at mid-month.⁴ Book early and allow for days when weather closes a road or a tour.

January and February sit in the middle of the season. The caves have had weeks of frost behind them, temperatures at the station hover around freezing at night, and daylight grows from 5.4 to 8.5 hours over those weeks.⁴ It is the middle ground between the darkest weeks and the late-season thaw.

March and April bring longer days, 11.6 and 15 hours at mid-month, and still fall inside Ice Explorers' October to April window.⁴ ¹ The longer light makes the drive easier and leaves time for the lagoon and the beach on the same day, but the end of the season depends on how quickly the thaw arrives.

An ice cave in Iceland in summer

If you travel between June and September, the lagoon caves are not an option, but an ice cave in Iceland in summer is still possible. Operators of the Katla cave near Vík say it is open every month of the year, and Visit South Iceland lists year-round ice cave explorations on Mýrdalsjökull.⁵ ¹⁴ Access can still be limited by weather or glacier conditions.⁵

The man-made tunnel in Langjökull is the other summer answer. Its operator says the tunnel is maintained year-round and remains accessible at any time of the year.⁶ In summer the glacier vehicle ride is shorter, about 30 minutes each way against 75 minutes in winter, and a rough gravel road from Húsafell to the Klaki base camp opens only from 1 June to 15 October.¹⁵ ¹⁶

At the lagoon, summer means a glacier walk instead. Ice Explorers runs its Ice Exploration Tour from May to September, lasting 4 to 4.5 hours, with a minimum age of 10.¹⁰ You will not walk into a cave, but you will see the same blue ice from the outside, under far longer days.

Shrinking glaciers, shifting caves

The seasons sit on top of a longer trend. Vatnajökull National Park says the southern outlet glaciers of Vatnajökull reached their largest size of the last ten millennia only 130 years ago and are now retreating and thinning at unprecedented rates.¹⁷ It adds that Icelandic glaciers could lose half of their volume by 2100.¹⁸

The Icelandic Meteorological Office put numbers on it in 2018: Icelandic glaciers had lost approximately 250 cubic kilometers of ice since 1995, about 7% of their total volume, and their area had shrunk by more than 600 km2 since 2000.¹⁹ ²⁰ Breiðamerkurjökull, where the lagoon caves form, retreats faster still where it calves into Jökulsárlón, by up to 200-300 m a year.²¹

For a visitor this has practical consequences. The caves of any given winter are unique and will not return in the same shape, and the places where guides find them move with the ice. Check recent information from your operator rather than relying on a photo from a past season, and expect the walk to the cave to vary from year to year.

Weather, cancellations and safety

Every ice cave tour depends on the day. Ice Explorers says its trips are weather and condition dependent and that it may change the itinerary or cancel before the tour starts with safety in mind.²² Some lagoon listings add that the national park authorities can stop a tour when they judge conditions unsafe.

Vatnajökull National Park warns that weather can change suddenly and that roads can deteriorate from flooding, sandstorms and even snow at any time of year.²³ For winter it recommends crampons and suitable tires, such as winter, all-year or studded tires.²⁴ Safetravel adds: keep your plans flexible and be ready to change or cancel them.²⁵

So build slack into a winter itinerary. Put the cave tour early in your stay near the lagoon, keep a spare day if you can, and choose a listing with free cancellation; the tour this site sells allows it up to 24 hours before. If a tour is cancelled by the operator for safety, check the listing's own refund terms, which vary between operators.

This winter's cave