Warm enough to swim? Juneau month by month
| Month | Daily high | Daily average | Verdict |
|---|---|---|---|
| January | 34°F | 30°F | Off-season |
| February | 37°F | 32°F | Off-season |
| March | 39°F | 35°F | Off-season |
| April | 49°F | 42°F | Off-season |
| May | 57°F | 50°F | Heater territory |
| June | 62°F | 56°F | Heater territory |
| July | 63°F | 57°F | Heater territory |
| August | 62°F | 57°F | Heater territory |
| September | 56°F | 51°F | Heater territory |
| October | 48°F | 44°F | Off-season |
| November | 40°F | 36°F | Off-season |
| December | 36°F | 33°F | Off-season |
Verdicts follow the daily average: 68°F+ is comfortable for most people, 75°F+ is prime, and below 62°F you're in heater territory. An unheated pool's water tends to sit near the recent daily average, a touch above it in spring and below in fall.
Reading the Juneau pool year
Pool life in Juneau is built around heat management, not calendar dates. The three levers, in order of value: a well-sized heater (start with the heater cost & sizing calculator — cost per session here is very sensitive to target temperature), a solar or insulating cover to keep overnight losses from erasing the day's gains, and wind protection, which matters more than most owners expect. Budget swimming around July and treat anything more as a bonus.
Frequently asked questions
Can you have an outdoor pool in Juneau?
Yes, but plan around heat from day one: Juneau's warmest month (July) averages only about 57°F, so an unheated pool rarely gets past brisk. A gas heater or high-output heat pump plus a good cover makes a real July-centered season possible.
When is the best time to swim outdoors in Juneau?
July is the peak, with the weeks either side as shoulder season. Check the month-by-month table on this page — and size your heater with our heater calculator before trusting any promise about "extending the season."
Where do these Juneau dates come from?
From 1991–2020 NOAA temperature records at the Juneau Dwtn station, 1 km from central Juneau. The working assumption: pools become pleasant as daily average air temperature passes 62–68°F, since water lags air by a week or two. A heater, cover, screened enclosure, or an unusually sunny yard all shift the real dates.