United States: where to swim in December?
United States, in December: the sea is at 16.1 °C on average along the coast, from 9.2 °C to 23.7 °C depending on the spot. Where the water is warmest (23.7 °C), it is warm. Ideal for long swims and for being in the water all day.
Sea temperature, month by month
| Month | Average temperature | Depending on the spot | Where it is warmest |
|---|---|---|---|
| January | 14.4 °C | 7.1 °C – 22.1 °C | pleasant |
| February | 13.8 °C | 5.4 °C – 21.7 °C | pleasant |
| March | 14.5 °C | 5.6 °C – 22.4 °C | pleasant |
| April | 16.1 °C | 7.5 °C – 24.2 °C | warm |
| May | 18.5 °C | 11.0 °C – 26.0 °C | warm |
| June | 21.2 °C | 12.5 °C – 28.8 °C | very warm |
| July | 23.2 °C | 13.8 °C – 29.9 °C | very warm |
| August | 23.8 °C | 14.7 °C – 30.4 °C | very warm |
| September | 23.0 °C | 14.5 °C – 29.4 °C | very warm |
| October | 21.2 °C | 13.5 °C – 28.2 °C | very warm |
| November | 18.2 °C | 11.5 °C – 25.6 °C | warm |
| December | 16.1 °C | 9.2 °C – 23.7 °C | warm |
Compared with November, the water cools down by 2.1 °C in December. The warmest month: August (23.8 °C). The coldest: February (13.8 °C).
Where the water is warmest in December
- Hawaii 25.4 °C · warm
- Florida 22.9 °C · warm
- Texas 20.6 °C · warm
- Alabama 19.7 °C · pleasant
- South Carolina 19.5 °C · warm
- Louisiana 19.4 °C · warm
- North Carolina 18.5 °C · warm
- Georgia 17.8 °C · pleasant
- California 14.2 °C · cool
- Virginia 11.5 °C · cold
- Oregon 11.1 °C · cold
- New Jersey 10.7 °C · cold
- New York 10.7 °C · cold
- Washington 9.9 °C · cold
- Maryland 9.6 °C · cold
- Massachusetts 9.2 °C · cold
- Maine 8.7 °C · very cold
- Alaska 2.7 °C · very cold
And right now?
For the temperature measured right now, station by station and to the hour: United States: water temperature
Frequently asked questions
What is the sea temperature in December?
United States, in December: 16.1 °C on average along the coast, from 9.2 °C in the coolest waters to 23.7 °C in the warmest (average of the years 2011 to 2025).
Can you swim in December?
Where the water is warmest (23.7 °C), it is warm. Ideal for long swims and for being in the water all day.
What is the best month for swimming?
The water is warmest in August (23.8 °C on average) and coldest in February (13.8 °C). Where the water is warmest, it goes above 20 °C in these months: January, February, March, April, May, June, July, August, September, October, November, December.
Where is the water warmest in December?
The warmest in December: Hawaii (25.4 °C), Florida (22.9 °C), Texas (20.6 °C). The coolest: Alaska (2.7 °C).
Where do these temperatures come from?
These are averages of the sea surface temperature from 2011 to 2025, computed from NOAA satellite images (OISST, one value about every 50 km), in a 100 km strip along the coasts of the main country: distant territories (overseas, remote islands) are not counted. It is an estimate, not a measurement taken at the beach: lakes and rivers are not included.