Pool swim season in Juneau, AK
Juneau, AK: how long the pool season really is
An unheated pool in Juneau never reaches 78°F in a normal year. It peaks around 54°F in Jul. The air allows up to 0 swimmable months with a heater (no month).
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What each heater buys you in Juneau
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 0 | no month | $0 | $0 |
| Solar cover only | 0 | no month | $0 | $50 |
| Solar panels + cover | 0 | no month | $0 | $283 |
| Heat pump + cover | 0 | no month | $0 | $550 |
| Gas heater + cover | 0 | no month | $0 | $425 |
For a 450 sq ft pool held at 80°F, at AK prices of 27.3¢/kWh electricity and $13/Mcf gas. All-in spreads the purchase over the equipment's life.
Do you need a pool heater in Juneau?
No. Your pool is already warm for every month the air allows. A heater adds nothing.
No heater makes outdoor swimming practical here: the air is too cold in every month. If you want to swim at home, price an enclosure or an indoor pool instead, and see why a cover cannot fix this and where solar panels stop working.
Weather station: Annex Creek, 4.7 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Juneau month by month: air, sun and pool water
| Month | Air high | Air avg | Sun kWh/m²/day | Water, unheated | Water, covered | Heat pump $ | Gas $ |
|---|---|---|---|---|---|---|---|
| Jan | 29° | 24° | 0.3 | 22° | 28° | – | – |
| Feb | 32° | 28° | 1.0 | 24° | 30° | – | – |
| Mar | 37° | 32° | 2.1 | 29° | 35° | – | – |
| Apr | 46° | 40° | 3.6 | 36° | 42° | – | – |
| May | 54° | 47° | 4.7 | 45° | 51° | – | – |
| Jun | 59° | 52° | 4.9 | 51° | 57° | – | – |
| Jul | 59° | 53° | 4.3 | 54° | 60° | – | – |
| Aug | 59° | 52° | 3.4 | 53° | 59° | – | – |
| Sep | 53° | 48° | 2.2 | 49° | 55° | – | – |
| Oct | 45° | 41° | 1.1 | 43° | 49° | – | – |
| Nov | 35° | 31° | 0.5 | 34° | 40° | – | – |
| Dec | 29° | 26° | 0.2 | 26° | 32° | – | – |
Sunshine peaks in Jun at 4.9 kWh/m²/day (NASA satellite data, 23.5 km grid cell). Highlighted months are swimmable with no heater.
How Juneau compares with nearby cities
Juneau ranks 4 of 4 Alaska cities for unheated swim months, and no nearby city gets a longer unheated season.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Anchorage, AK | 558 mi | 0 | 0 | $0 |
| Wasilla, AK | 571 mi | 0 | 0 | $0 |
| Fairbanks, AK | 626 mi | 0 | 2 | $453 |
| Lynden, WA | 806 mi | 0 | 4 | $373 |
| Ferndale, WA | 809 mi | 0 | 2 | $137 |
| Bellingham, WA | 818 mi | 0 | 2 | $129 |