Is Silfra Snorkeling Cold? What 2 °C Water Feels Like at Thingvellir
The short answer. Yes. The water in Silfra stays at 2–4 °C all year, summer and winter. You do not feel most of it, because you wear a drysuit over a warm undersuit, with a hood and gloves, and only your face meets the water. Your hands feel it through the gloves. A hot drink waits at the end.
Cold is the question that stops most Silfra bookings. It is a fair one: the fissure is fed by glacial groundwater, and it never warms up. Here is what the cold is like, what keeps it out, and what you can do about the parts it reaches. Every snorkel fare is compared on Thingvellir Tours.
How cold is the water in Silfra?
Between 2 and 4 °C, all year round. It does not change with the season, because the water does not come from rain or snowmelt on the surface. It comes up from under the lava.
Silfra is a fissure in the northern part of the lake, at most 10 m wide and reaching 60 m deep. Its name means "silver", for the clarity of the water.
Why does it never warm up?
The water is groundwater from the Langjökull glacier. It spends about 30 years travelling underground through the lava before it surfaces in the fissure. By the time you are floating in it, it has had three decades in the dark at the temperature of the rock.
That same journey filters it, which is why it is so clear. The cold and the clarity come as a pair.
The lake the fissure opens into works the same way. About 90% of the water flowing into Þingvallavatn travels underground, and water from Langjökull takes 20 to 30 years to arrive. The nature page explains the lake and the rift around it.
Did you know? Silfra is part of the rift zone, not the boundary itself. The plates are roughly five kilometres apart, so you cannot touch both continents at once. You are snorkelling in the zone between the North American plate and the Hreppar microplate.
What do you wear?
The park requires full cold-water exposure protection. On the drysuit snorkels, that means a warm undersuit next to your skin, a drysuit over it, and a hood, gloves, mask, snorkel and fins. The Troll fare lists all of these, and the DIVE.IS fare lists the drysuit and warm undersuit. The suit keeps you dry, not wet, so the undersuit stays warm.
The park allows snorkellers to use a thick wetsuit instead. The Adventure Vikings tour from Reykjavík is sold as a wetsuit snorkel; bring swimwear and a towel for it, since both are excluded from the fare.
- Drysuit snorkels: you stay dry inside the suit, and the undersuit holds your warmth.
- Wetsuit snorkel: a thin layer of water sits against your skin, so you feel more of the cold.
- Both: your face is the part of you that meets the water.
What does the cold feel like?
Inside a drysuit, your body stays dry. Your face does not. The mask covers your eyes and nose, and the rest of your face is in water at 2–4 °C. That is where you feel the cold first.
Your hands feel it next, through the gloves. You float on the surface, face down, looking into water clear enough to see the lava walls below you. For most of the swim, the view is what holds your attention.
How long are you in the water?
The Adventure Vikings fare gives 40 minutes in the fissure. The whole DIVE.IS snorkel runs two and a half hours, and the Troll one three hours; much of that is briefing, changing and the walk to the entry platform.
The DIVE.IS route takes you through Silfra Hall and the Cathedral and finishes in the Silfra Lagoon. That is long enough to get cold hands and short enough that nobody minds.
Does winter make it colder?
The water, no. The air, yes. The park's weather record from station 945, between 1949 and 1983, gives January a mean of −2.6 °C and July a mean of 10.5 °C; recent decades run warmer. In winter, the cold you notice is on the walk to and from the water, and while you change.
That is why the heated changing van matters. The weather page covers each month, and the winter guide covers snorkelling in the dark months.
How do you warm up afterwards?
Each snorkel fare builds in a warm-up. DIVE.IS has a heated changing van, with hot chocolate and cookies back at the vans. Troll serves hot chocolate or tea and a chocolate bar after the snorkel. Adventure Vikings includes hot chocolate.
Bring a dry warm layer and a hat to put on the moment the suit comes off. That, more than anything, decides how you feel on the drive home.
Where do you get in and out?
Silfra is reached from car park P5, Valhöll, the car park nearest the church and the fissure. Road 361 runs into the park towards the Silfra car park, and the self-drive snorkels meet there: DIVE.IS at the Silfra car park, Troll by P5.
If you drive yourself, you pay the park's parking fee of 1,000 ISK a car for the day. Cameras read your plate, and you pay at a machine or online at Checkit.is. The Troll fare leaves parking out, so budget for it. The map page shows where P5 sits, and visiting the park lists every fee.
The snorkel fares compared
| Fare | From | Start | Suit | Warm-up |
|---|---|---|---|---|
| Snorkel, meet on location | From $159 | Silfra car park, you drive | Drysuit, warm undersuit | Heated van, hot chocolate |
| Snorkel, self-drive, photos | From $149 | By P5, you drive | Drysuit, undersuit, hood, gloves | Hot chocolate or tea |
| Snorkel from Reykjavík, photos | From $219 | Pickup in Reykjavík | Wetsuit | Hot chocolate |
| Dive, certified divers | From $349 | Hotel pickup | Drysuit, warm undersuit | Heated van, hot chocolate |
Who can snorkel in Silfra?
Snorkellers must be 12 or older, and 14 on the adult band of the Adventure Vikings fare. DIVE.IS asks for a height of 150 cm or more, and Troll 135 cm or more. Everyone fills in a medical screening form, and nobody goes in alone: the park's buddy rule applies.
Diving is stricter. Divers need an autonomous-diver licence plus a drysuit certificate, or 10 logged drysuit dives in the past two years, and may go no deeper than 18 m. Silfra snorkeling tours sets out every fare, and things to do puts Silfra beside the rest of the park.
Ready for the cold? The three below cover a drysuit snorkel, a wetsuit snorkel with pickup, and a dive; every other fare is on Thingvellir Tours.
Silfra fares for every tolerance of cold
Silfra: Snorkeling Between Tectonic Plates - Meet on Location
Meet your guide at the Silfra car park, change in a heated van and snorkel in a drysuit. The permit is in the fare.
From $159 per person
Check Availability
Silfra Wetsuit Snorkeling Tour with Underwater Photos - From Reykjavik
Pickup in Reykjavík, 40 minutes in the fissure, underwater photos, and six snorkellers at most.
From $219 per person
Check Availability
Silfra: Diving Between Tectonic Plates and Pick Up from Reykjavik
For certified drysuit divers: hotel pickup, a PADI instructor, a warm undersuit and a heated changing van.
From $349 per person
Check Availability