Coldest oceans by average sea temperature
Same five oceans, sorted from coldest to warmest. The Southern Ocean wins the cold contest. The Arctic finishes second. The contest between Atlantic and Pacific for mid-table is closer than you might think.
Coldest ocean
Southern Ocean
-1.0°C annual mean across 44 coastal locations
Polar spread
29°C
between the warmest and the coldest ocean
The ranking, coldest first
Each row is the mean of every location we track inside that ocean's rough basin. The Southern Ocean and the Arctic are dominated by ice-bound coasts and only thaw briefly. The Atlantic and Pacific are the most variable from north to south.
| # | Ocean | Annual mean | Coldest month | Warmest month | Locations |
|---|---|---|---|---|---|
| 1 | Southern Ocean | -1.0°C | August(-1.6°C) | February(-0.2°C) | 44 |
| 2 | Arctic Ocean | 2.9°C | March(0.5°C) | August(7.4°C) | 264 |
| 3 | Atlantic Ocean | 16.5°C | February(12.8°C) | August(20.9°C) | 6,268 |
| 4 | Pacific Ocean | 18.2°C | February(14.2°C) | August(22.4°C) | 6,827 |
| 5 | Indian Ocean | 27.6°C | February(26.3°C) | May(28.3°C) | 3,789 |
Latest sea temperatures around the world
Cool pins crowd the high latitudes, both north and south. The cold spots in Europe and North America (the Baltic, the Great Lakes, the Gulf of St. Lawrence) are seasonal and warm up in summer. The polar pins barely move.
Southern Ocean
Annual mean -1.0°C across 44 locations
The coldest ocean coastlines on the planet sit here, almost all of them in Antarctica. Most stay below freezing for most of the year. Anyone swimming in this water is doing it for the rush, not the comfort.
- Warmest month February -0.2°C
- Coldest month August -1.6°C
- Annual mean -1.0°C
- Months above 20°C 0 of 12
Top 10 coldest locations in the southern ocean
Sorted by year-round average across the past ten years of daily readings.
| # | Location | Country | Annual mean |
|---|---|---|---|
| 1 | Weddell Sea Argentine Antarctica | Argentina | -1.8°C |
| 2 | Ronne Ice Shelf Argentine Antarctica | Argentina | -1.8°C |
| 3 | Syowa Queen Maud Land | Antarctica | -1.8°C |
| 4 | Gauss Station Australian Antarctic Territory | Antarctica | -1.7°C |
| 5 | Whiskey Bay Argentine Antarctica | Antarctica | -1.7°C |
| 6 | Scott Base Ross Dependency | Antarctica | -1.7°C |
| 7 | Shackleton Base Ross Dependency | Antarctica | -1.7°C |
| 8 | Zhong Shan Larsemann Hills | Antarctica | -1.7°C |
| 9 | Commonwealth Bay Adélie Land | Antarctica | -1.7°C |
| 10 | Mawson Australian Antarctic Territory | Antarctica | -1.7°C |
Arctic Ocean
Annual mean 2.9°C across 264 locations
Northern Russia, Greenland, and the Canadian Arctic dominate this list. Brief late-summer warmth can push temperatures into low single digits, but winters return to near or below freezing.
- Warmest month August 7.4°C
- Coldest month March 0.5°C
- Annual mean 2.9°C
- Months above 20°C 0 of 12
Top 10 coldest locations in the arctic ocean
Sorted by year-round average across the past ten years of daily readings.
| # | Location | Country | Annual mean |
|---|---|---|---|
| 1 | Wrangel Bay Nunavut | Canada | -1.6°C |
| 2 | Cameron Island Nunavut | Canada | -1.6°C |
| 3 | Alert Nunavut | Canada | -1.6°C |
| 4 | Cape Sheridan Nunavut | Canada | -1.6°C |
| 5 | Discovery Harbour Nunavut | Canada | -1.6°C |
| 6 | Iceberg Point Nunavut | Canada | -1.6°C |
| 7 | Airstrip Point Nunavut | Canada | -1.6°C |
| 8 | Isachsen Nunavut | Canada | -1.5°C |
| 9 | Hamilton Island Nunavut | Canada | -1.4°C |
| 10 | Pim Island Nunavut | Canada | -1.4°C |
Atlantic Ocean
Annual mean 16.5°C across 6,268 locations
The coldest Atlantic coasts cluster in the north: Greenland, Labrador, Iceland, the North Sea, the Baltic. The southern tip of the Atlantic, off the Falklands and Tierra del Fuego, also lands here.
- Warmest month August 20.9°C
- Coldest month February 12.8°C
- Annual mean 16.5°C
- Months above 20°C 3 of 12
Top 10 coldest locations in the atlantic ocean
Sorted by year-round average across the past ten years of daily readings.
| # | Location | Country | Annual mean |
|---|---|---|---|
| 1 | Southern Thule | South Georgia and the South Sandwich Islands | -0.7°C |
| 2 | Iqaluit Nunavut | Canada | -0.5°C |
| 3 | Frobisher's Farthest Nunavut | Canada | -0.5°C |
| 4 | Iqaluit (Frobisher Bay) Nunavut | Canada | -0.5°C |
| 5 | Resor Island Nunavut | Canada | -0.5°C |
| 6 | Lewis Bay Nunavut | Canada | -0.5°C |
| 7 | Port Burwell Nunavut | Canada | -0.4°C |
| 8 | Brevoort Harbour Nunavut | Canada | -0.3°C |
| 9 | Williams Harbour Newfoundland and Labrador | Canada | -0.2°C |
| 10 | Lake Harbour Nunavut | Canada | -0.2°C |
Pacific Ocean
Annual mean 18.2°C across 6,827 locations
The coldest Pacific places are in the far north (Alaska, the Bering Sea, the Sea of Okhotsk) and the far south off Chile and southern Argentina.
- Warmest month August 22.4°C
- Coldest month February 14.2°C
- Annual mean 18.2°C
- Months above 20°C 4 of 12
Top 10 coldest locations in the pacific ocean
Sorted by year-round average across the past ten years of daily readings.
| # | Location | Country | Annual mean |
|---|---|---|---|
| 1 | King Charles Cape Nunavut | Canada | -0.6°C |
| 2 | Port de Boucherville Nunavut | Canada | -0.1°C |
| 3 | Eldorado Saskatchewan | Canada | 0.2°C |
| 4 | Goldfields Saskatchewan | Canada | 0.2°C |
| 5 | Great Bear Lake Northwest Territories | Canada | 0.2°C |
| 6 | Ashe Inlet Nunavut | Canada | 0.3°C |
| 7 | Doctor Island Nunavut | Canada | 0.4°C |
| 8 | Yellowknife Northwest Territories | Canada | 0.4°C |
| 9 | Quaqtaq (Koartac) Quebec | Canada | 0.6°C |
| 10 | Digges Harbour Nunavut | Canada | 0.7°C |
Indian Ocean
Annual mean 27.6°C across 3,789 locations
Even the coldest Indian Ocean coasts are warmer than most northern Atlantic or Pacific places. Sub-Antarctic islands and the southern coast of South Africa make up the bottom of this list.
- Warmest month May 28.3°C
- Coldest month February 26.3°C
- Annual mean 27.6°C
- Months above 20°C 12 of 12
Top 10 coldest locations in the indian ocean
Sorted by year-round average across the past ten years of daily readings.
| # | Location | Country | Annual mean |
|---|---|---|---|
| 1 | Heard Island Australian external territory | Australia | 2.7°C |
| 2 | Kitimat Kitimat-Stikine | Canada | 5.0°C |
| 3 | Anse Betsy | French Southern and Antarctic Lands | 5.1°C |
| 4 | Crozet-B | French Southern and Antarctic Lands | 5.7°C |
| 5 | Marion Island Western Cape | South Africa | 6.2°C |
| 6 | St. Paul Island Pribilof Islands | United States | 14.8°C |
| 7 | Pieman River Tasmania | Australia | 15.0°C |
| 8 | Stack Island Tasmania | Australia | 15.1°C |
| 9 | Three Hummock Island Tasmania | Australia | 15.2°C |
| 10 | Kingston South Australia | Australia | 15.3°C |
Top 25 coldest coastal locations on Earth
The coldest single coastal locations in our sample are almost all in Antarctica and the Arctic. Year-round averages near or below freezing are normal. Click any place to see its 30-day chart and 10-year history.
| # | Location | Country | Annual mean | Latest |
|---|---|---|---|---|
| 1 | Weddell Sea Argentine Antarctica | Argentina | -1.8°C | -1.8°C |
| 2 | Ronne Ice Shelf Argentine Antarctica | Argentina | -1.8°C | -1.8°C |
| 3 | Syowa Queen Maud Land | Antarctica | -1.8°C | -1.6°C |
| 4 | Gauss Station Australian Antarctic Territory | Antarctica | -1.7°C | -1.8°C |
| 5 | Whiskey Bay Argentine Antarctica | Antarctica | -1.7°C | -1.7°C |
| 6 | Scott Base Ross Dependency | Antarctica | -1.7°C | -1.7°C |
| 7 | Shackleton Base Ross Dependency | Antarctica | -1.7°C | -1.7°C |
| 8 | Zhong Shan Larsemann Hills | Antarctica | -1.7°C | -1.7°C |
| 9 | Commonwealth Bay Adélie Land | Antarctica | -1.7°C | -1.7°C |
| 10 | Mawson Australian Antarctic Territory | Antarctica | -1.7°C | -1.8°C |
| 11 | Wrangel Bay Nunavut | Canada | -1.6°C | -1.7°C |
| 12 | Wilkes Station Wilkes Land | Antarctica | -1.6°C | -1.6°C |
| 13 | Cameron Island Nunavut | Canada | -1.6°C | -1.7°C |
| 14 | Port Martin Adélie Land | Antarctica | -1.6°C | -1.7°C |
| 15 | Breivika Queen Maud Land | Antarctica | -1.6°C | -1.6°C |
| 16 | Alert Nunavut | Canada | -1.6°C | -1.5°C |
| 17 | Cape Sheridan Nunavut | Canada | -1.6°C | -1.7°C |
| 18 | Dumont d'Urville Base Adélie Land | Antarctica | -1.6°C | -1.8°C |
| 19 | Casey Australian Antarctic Territory | Antarctica | -1.6°C | -1.6°C |
| 20 | Kainan Bay Ross Dependency | Antarctica | -1.6°C | -1.7°C |
| 21 | Discovery Harbour Nunavut | Canada | -1.6°C | -1.6°C |
| 22 | Iceberg Point Nunavut | Canada | -1.6°C | -1.7°C |
| 23 | Pastorizo Bay Argentine Antarctica | Antarctica | -1.6°C | -1.6°C |
| 24 | Airstrip Point Nunavut | Canada | -1.6°C | -1.7°C |
| 25 | Isachsen Nunavut | Canada | -1.5°C | -1.7°C |
A word on cold-water swimming
Water below 10°C is genuinely dangerous if you're not used to it. Cold shock can affect breathing and judgement within seconds. Even strong swimmers can struggle in water below 5°C without a wetsuit and a plan. Build up tolerance slowly, swim with company, and treat the early seconds with respect. Most of the "I jumped in and it was fine" stories were written by people who got lucky once.