Guide · Clothing

What to wear in a lava cave, in any season

A lava tube is cold, damp and uneven whatever the weather outside. A few sensible layers and the right shoes make the difference between shivering through the hour and enjoying it.

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Editorial team, lavacavetouriceland.comUpdated October 25, 20266 min read18 sources

The tour that goes with it Raufarhólshellir lava tube walk 4.7 (1,956 reviews) 1 hourHelmets and headlamps includedCrampons in winter from$72per person Check availabilityFree cancellation up to 24 hrs before

Pack this

01Air inside: Around 0 to 4 °C in Raufarhólshellir, all year.¹
02Top half: Warm layers and a water-resistant or waterproof jacket.²
03Feet: Sturdy shoes, ideally hiking shoes; ankle boots for caving.³
04Provided: Helmet and headlamp, plus crampons in winter.
05Outside: Layers with wool close to the body and a windproof shell.⁴

The short answer: dress for a cold room that drips

If you remember one thing about what to wear in a lava cave, make it this: the cave does not care what season it is. The operator of Raufarhólshellir gives the temperature inside as around 0 to 4 degrees Celsius and warns that water sometimes drips from the ceiling.¹ That is the climate of a cold, damp cellar, and it is the same on a bright July afternoon as on a dark January morning.

The operator's own advice is short and sensible. Helmets and lights are provided; warm clothes and sturdy shoes are recommended; and because water usually drips from the ceiling, a water-resistant or waterproof jacket is a good idea.² Add a hat that fits under the helmet and a pair of gloves, and you have everything the 1-hour walk asks of you.

Other caves are no warmer. At Vatnshellir on Snæfellsnes the operator says the temperature stays just above freezing year-round and recommends gloves.⁵ The Arnarker caving listing says its cave rarely goes above 4°C, even in summer, and a Víðgelmir tour puts that cave at approximately 4°C year-round. Wherever you go underground in Iceland, plan for a fridge.

Layers: what the cold air asks for

Layering is the answer in a cave, just as it is outside. Visit South Iceland calls layering the key to dressing well in Iceland at any time of year, with wool close to the body and a wind- and waterproof outer shell.⁴ For a cave that means a thin wool or synthetic base layer, a warm mid-layer such as a fleece or a wool sweater, and a shell on top that keeps the drips off.

The reason layers work so well is that you can adjust them. In the car or on the bus you may be warm; standing still in the cave while the guide explains the rock, you cool down quickly. Open or close the jacket as you go. Avoid cotton next to your skin if you can: once damp, it stays cold, and a lava tube is a damp place even when the floor looks dry.

Think about your head and hands too. A thin beanie fits under the helmet and keeps a surprising amount of warmth in. Gloves help on cold metal railings and stairs, and at Vatnshellir both the operator and the Environment Agency of Iceland recommend them.⁵ ⁶ If you run cold, a scarf or neck warmer takes up no space in a pocket and makes the hour noticeably more comfortable.

Temperature

Inside the caves, outside in Reykjavík

°C

Cave temperatures as the operator and the Arnarker listing state them; the highs are NOAA averages for the Reykjavík city station, about 32 km from the cave, 1991 to 2020.¹ ⁷

Month by month

The weather outside the cave

Month	Daylight (h)	Darkness (h)	High / low	Wet days	At the cave
Jan	5.4	18.6	3 / -2 °C	12	daily tours
Feb	8.6	15.4	3 / -2 °C	13	daily tours
Mar	11.6	12.4	4 / -1 °C	11	daily tours
Apr	14.9	9.1	7 / 1 °C	8	daily tours
May	18.2	5.8	10 / 4 °C	8	daily tours
Jun	20.8	3.2	13 / 7 °C	6	daily tours
Jul	19.7	4.3	15 / 9 °C	7	daily tours
Aug	16.5	7.5	14 / 9 °C	9	daily tours
Sep	13.2	10.8	11 / 6 °C	11	daily tours
Oct	10	14	8 / 3 °C	10	daily tours
Nov	6.7	17.3	5 / 0 °C	12	daily tours
Dec	4.4	19.6	3 / -2 °C	12	daily tours

Highs, lows and wet days (2.5 mm or more) are NOAA averages for the Reykjavík city station, about 32 km from the cave, 1991 to 2020; mid-month daylight is our own calculation.⁷ Season according to the cave's operator.¹⁸

Three outfits

What to wear by season and trip

Light layers

Summer walk

The 1-hour footbridge walk

Base: Thin wool layer
Top: Fleece and rain shell
Feet: Trainers with tread

See the walk

Warm and grippy

Winter walk

Ice at the entrance

Base: Thermal layer
Top: Insulated jacket
Feet: Boots, crampons given

See the walk

Built for rock

Caving trip

Lava falls or Arnarker

Base: Thermal layer
Top: Extra mid-layer, shell
Feet: Ankle boots, required

See the walk

Decision helper

What you need for your trip

Find your situation and pack accordingly

I am doing the footbridge walk in summer I am visiting in midwinter I booked the lava falls trip I am going to Vatnshellir I only have city shoes

Layers and a shell

The cave stays around 0 to 4 °C with drips.¹

Add grips and a warm jacket

Visit South Iceland recommends ice cleats or anti-slip soles.⁸

Ankle boots

Sneakers or low-cut shoes are not allowed.⁹

Gloves, no headlamp

Gloves are recommended; headlamps are not permitted.⁵ ¹⁰

Buy or borrow boots

The operator recommends good hiking shoes.³

Helmets and lights provided. Warm clothes and sturdy shoes are recommended and bear in mind that there is usually some water dripping from the ceiling so wearing a water resistant or water proof jacket/clothes is recommended.

The Lava Tunnel (Raufarhóll ehf)Source 2

Shoes: grip first, style last

Footwear matters more than any other piece of clothing. Inside Raufarhólshellir much of the tunnel is covered in large rocks, and although a footbridge and paths cross the roughest terrain, there are steps, damp metal and, in winter, ice near the entrance.¹¹ The operator recommends good hiking shoes for the standard walk.³ Trainers with a solid tread will do; smooth city soles will not.

On rougher trips the rules get stricter. For the Lava Falls Adventure Tour in Raufarhólshellir, hiking boots with ankle support are required, and the operator says sneakers or low-cut shoes are not allowed.³ ⁹ The Arnarker listing also requires hiking boots with ankle support. At Vatnshellir high heels, flat-bottom shoes and flip-flops are not allowed for safety.⁵

Visit South Iceland puts waterproof and sturdy walking shoes with a good tread on its year-round packing list for Iceland, so the same pair can serve you in the cave and on the rest of your trip.¹² Break them in before you arrive, wear thick socks, and if you travel in winter, remember that the operator's listing includes crampons for the cave.

Checklist

Your lava cave packing list

Wear

Wool or synthetic base layer
Fleece or wool mid-layer
Water-resistant or waterproof jacket

Add

Thin hat to fit under a helmet
Gloves for railings and rock
Hiking shoes with a good tread

Leave behind

Heels, flip-flops and smooth soles
Jewelry and anything precious
Your own headlamp at Vatnshellir

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Raufarhólshellir1-hour walkfrom $72 RaufarhólshellirWith coachfrom $68 Vatnshellir45-minute tourfrom $46

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Our sum: the trip's cheapest GetYourGuide fare multiplied by how many cavers you enter, converted with the ECB's figure for the day. The exact amount shows once you pick a date.

Video

A layering system for Icelandic weather

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Rain shell, gloves and the helmet

Water is the part visitors forget. In Raufarhólshellir water usually drips from the ceiling, and the operator recommends a water-resistant or waterproof jacket for that reason.² The Leiðarendi caving listing likewise asks you to wear a waterproof jacket in the cave, and the Arnarker listing recommends one too. A light rain shell over your warm layer solves the problem.

You do not need to bring a helmet or a light for the walk sold on this site: the listing includes helmets and headlamps, and crampons in winter. Leave your own headlamp in your bag at Vatnshellir, where helmets and flashlights are provided and, for safety reasons, headlamps are not permitted.¹⁰ On the caving trips, check each listing for what it provides and what it expects you to bring.

Keep your hands free. A small backpack or a jacket with deep pockets is better than a handbag, because you may want a hand on a railing or on the rock. Put your phone or camera on a wrist strap, and wipe the lens before photos, since drips and cold air can mist it. A spare pair of dry gloves in a pocket is a small luxury in winter.

Dressing for the weather outside, month by month

The outside weather decides what you wear to and from the cave. At the Reykjavík weather station, the city's own and not the cave's, daily highs average 14.9 °C in July and 3.2 °C in January.⁷ The table on this page gives every month, with the highs, the lows and the number of wet days, so you can see how little the warm season really differs from the cold one.

Winter adds ice. Visit South Iceland recommends an insulated jacket in winter along with ice cleats, ice grips or anti-slip soles for better traction.⁸ The parking area and the path to the entrance can be slippery when frozen, and the operator says ice sculptures form inside the entrance of the cave every winter.¹³ The crampons included in the listing cover the cave itself.

Summer is milder but not warm. Visit South Iceland reminds visitors that Icelandic summers are cool rather than hot, with evenings that can feel quite cold, and to be prepared for quickly changing conditions in every season.¹⁴ ¹⁵ A day that starts sunny in Reykjavík can be windy and wet on the heath by the cave. Bring the same layers in July as in October, and simply wear fewer of them in the car.

Extra kit for caving trips

The rough caving trips ask for more. The Lava Falls Adventure Tour in Raufarhólshellir requires hiking boots with ankle support and warm clothes, provides helmets, headlights and, in winter, crampons, and spends 3 to 4 hours underground on average.¹⁶ Over that time the cold adds up, so an extra mid-layer is worth more than you think.

For Arnarker the listing asks for good physical shape and balance, hiking boots with ankle support and a waterproof jacket, and warns the cave rarely goes above 4°C even in summer. Visit South Iceland adds that exploring Arnarker needs good hiking gear, a helmet and a headtorch.¹⁷ Choose trousers that move well and that you do not mind scuffing on sharp lava, and gloves with grip.

On every caving trip, the rule is the same: nothing loose, nothing precious, nothing that hampers your hands. Leave jewelry at the hotel, tie long hair back under the helmet, and carry water and a small snack in a backpack. Lava rock is sharp and unforgiving, and the less you have to think about your clothes, the more you can enjoy the cave.

Under the lava