United States: where to swim in May?
United States, in May: the sea is at 18.5 °C on average along the coast, from 11.0 °C to 26.0 °C depending on the spot. Where the water is warmest (26.0 °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 April, the water warms up by 2.4 °C in May. The warmest month: August (23.8 °C). The coldest: February (13.8 °C).
Where the water is warmest in May
- Florida 25.9 °C · very warm
- Louisiana 25.5 °C · warm
- Alabama 25.3 °C · warm
- Hawaii 25.3 °C · warm
- Texas 25.3 °C · warm
- Georgia 23.5 °C · warm
- South Carolina 23.1 °C · warm
- North Carolina 21.9 °C · warm
- Maryland 16.0 °C · cool
- Virginia 16.0 °C · cool
- California 13.6 °C · cool
- New Jersey 13.4 °C · cold
- Oregon 12.1 °C · cold
- New York 11.9 °C · cold
- Washington 11.8 °C · cold
- Massachusetts 10.2 °C · cold
- Maine 8.1 °C · very cold
- Alaska 3.2 °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 May?
United States, in May: 18.5 °C on average along the coast, from 11.0 °C in the coolest waters to 26.0 °C in the warmest (average of the years 2011 to 2025).
Can you swim in May?
Where the water is warmest (26.0 °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 May?
The warmest in May: Florida (25.9 °C), Louisiana (25.5 °C), Alabama (25.3 °C). The coolest: Alaska (3.2 °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.