Site emblem: two old-fashioned swimmers
Water temperatureEnter

Alaska (United States): where to swim in August?

Alaska, in August: the sea is at 10.2 °C on average along the coast, from 4.2 °C to 13.9 °C depending on the spot. Where the water is warmest (13.9 °C), it is cold. You can swim, but the cold bites quickly: plan a short swim, or wear a wetsuit.

Sea temperature, month by month

MonthAverage temperatureDepending on the spotWhere it is warmest
January2.0 °C-1.6 °C – 6.0 °Cvery cold
February1.6 °C-1.7 °C – 5.6 °Cvery cold
March1.5 °C-1.7 °C – 5.2 °Cvery cold
April1.7 °C-1.7 °C – 5.8 °Cvery cold
May3.2 °C-1.3 °C – 7.8 °Cvery cold
June5.9 °C-0.4 °C – 10.7 °Ccold
July9.1 °C3.2 °C – 13.3 °Ccold
August10.2 °C4.2 °C – 13.9 °Ccold
September9.1 °C3.2 °C – 12.5 °Ccold
October6.7 °C1.4 °C – 10.3 °Ccold
November4.3 °C-0.7 °C – 8.4 °Cvery cold
December2.7 °C-1.6 °C – 7.0 °Cvery cold

Compared with July, the water warms up by 1.1 °C in August. The warmest month: August (10.2 °C). The coldest: March (1.5 °C).

Nearby, in August

And right now?

For the temperature measured right now, station by station and to the hour: Alaska: water temperature

Frequently asked questions

What is the sea temperature in August?

Alaska, in August: 10.2 °C on average along the coast, from 4.2 °C in the coolest waters to 13.9 °C in the warmest (average of the years 2011 to 2025).

Can you swim in August?

Where the water is warmest (13.9 °C), it is cold. You can swim, but the cold bites quickly: plan a short swim, or wear a wetsuit.

What is the best month for swimming?

The water is warmest in August (10.2 °C on average) and coldest in March (1.5 °C). Even where it is warmest, the water never reaches 20 °C in any month; the three warmest months are: August, July, September.

What temperature do you need to swim comfortably?

Below 15 °C the water is cold: the cold takes your breath away and tires you quickly. Between 20 °C and 25 °C most people find it pleasant. Below 10 °C it is very cold.

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.

← July · September → · Warmest water today