Sea temperature in Iceland
Live water temperatures and swimming conditions across 1 beaches on the Iceland coast.
Best time to swim in Iceland
The sea in Iceland peaks in August, when the water averages around 21°C.
The main swimming season runs from July – September, when surface temperatures stay comfortable for extended sessions.
On average, 3 months a year sit above 20°C — the threshold most swimmers describe as pleasant without a wetsuit.
Shoulder months like June and October are noticeably cooler but often quieter, with fewer crowds and steadier weather.
Outside peak season the water drops toward 14°C, so a 3/2mm shorty or full wetsuit makes long swims much more comfortable.
The coldest month is typically January at around 14°C, when cold-water swimmers dominate the coast.
Iceland sea temperature history
Long-term climatology for Iceland shows an annual mean sea temperature of 17°C, ranging from 14°C in winter to 21°C at the summer peak.
The seasonal swing is roughly 7°C between the coldest and warmest month — a useful yardstick when comparing years or checking whether the current sea is running above or below average.
Recent decades have trended slightly warmer at Iceland, in line with regional sea-surface temperature records for the wider basin.
Monthly averages below are drawn from multi-decadal climatology and are updated as new observations arrive.
Values are area averages; individual beaches vary by exposure and depth.
Iceland sea temperature: frequently asked questions
What is the warmest month to swim in Iceland?
August is the warmest month in Iceland, when the sea averages about 21°C. Late-season warmth often persists a few weeks after peak.
When is the sea coldest in Iceland?
The coldest month in Iceland is typically January, when the water averages around 14°C. Cold-water swimmers and surfers dominate this period.
When can you swim in Iceland without a wetsuit?
The main swimming season in Iceland runs from July – September — about 3 months a year when the sea sits above 20°C, the level most swimmers describe as pleasant without a wetsuit.
Do I need a wetsuit in Iceland?
Outside peak summer the water in Iceland drops toward 14°C, so a 3/2mm shorty or full wetsuit makes long swims much more comfortable. In peak months most swimmers go without.
What is the average sea temperature in Iceland?
The long-term annual mean sea temperature in Iceland is about 17°C, based on multi-decadal climatology of the surrounding waters.
How do I check the current sea temperature in Iceland?
The live reading at the top of this page shows the current sea temperature in Iceland, updated hourly from marine buoy and satellite data. The 7-day forecast covers water, air, waves, wind and UV for the week ahead.
Iceland sea temperature by month
Average sea temperatures around Iceland for every month of the year, based on long-term Open-Meteo marine climatology.
| Month | Average sea | Swimming comfort |
|---|---|---|
| January | 14.0°C | Bracing — wetsuit advised |
| February | 14.0°C | Bracing — wetsuit advised |
| March | 14.0°C | Bracing — wetsuit advised |
| April | 15.0°C | Bracing — wetsuit advised |
| May | 16.0°C | Bracing — wetsuit advised |
| June | 18.0°C | Swimmable, refreshing |
| July | 20.0°C | Swimmable, refreshing |
| August ⭐ | 21.0°C | Pleasant swimming |
| September | 21.0°C | Pleasant swimming |
| October | 19.0°C | Swimmable, refreshing |
| November | 17.0°C | Bracing — wetsuit advised |
| December | 15.0°C | Bracing — wetsuit advised |
Monthly figures are modelled climatology averages, not live readings. How accurate is our data?
Warmest beaches in Iceland right now
| Beach | Region | Sea | Swim score |
|---|---|---|---|
| Reynisfjara | South Coast | 21.2°C | Excellent |
Sea temperature in Iceland — FAQ
How warm is the sea in Iceland in September?
The sea off Iceland averages about 21.0°C in September, based on long-term monthly averages for this coast.
When is the best time to swim in Iceland?
Iceland is warmest in August (around 21.0°C) and coldest in January (around 14.0°C). There are typically 0 months a year when the water sits above 22°C.
What is the average yearly sea temperature in Iceland?
Across all twelve months, the sea in Iceland averages about 17.0°C.
Do you need a wetsuit to swim in Iceland?
The sea in Iceland stays below 22°C even at its warmest (~21.0°C in August), so a 3/2mm or thicker wetsuit is recommended for longer swims year-round.