Pool swim season in St. Petersburg, FL

When can you swim in an outdoor pool in St. Petersburg, FL?

An unheated pool in St. Petersburg reaches 78°F in May to Oct, about 6 months a year. The air allows up to 11 swimmable months with a heater (Feb to Dec).

1. J
2. F
3. M
4. A
5. M
6. J
7. J
8. A
9. S
10. O
11. N
12. D

What each heater buys you in St. Petersburg

For a 450 sq ft pool held at 80°F, at FL prices of 15.3¢/kWh electricity and $25/Mcf gas. All-in spreads the purchase over the equipment's life.

The cheapest way to the full season in St. Petersburg

Solar panels + cover: 10 of 11 possible months for about $283 a year all-in, which works out near $71 for each month it adds.

Before you pay for any heater, buy a solar cover: on its own it adds 2 months here for about $50 a year (why a cover comes first). If you get quotes, ask for a heat pump sized to your pool's surface area; here it beats gas all-in (heat pump or gas).

Weather station: St Petersburg, 1.2 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.

St. Petersburg month by month: air, sun and pool water

Heating costs most in Feb (about $82 with a heat pump, $274 with gas). Sunshine peaks in May at 6.8 kWh/m²/day (NASA satellite data, 32.5 km grid cell). Highlighted months are swimmable with no heater.

How St. Petersburg compares with nearby cities

St. Petersburg ranks 13 of 173 Florida cities for unheated swim months, and no nearby city gets a longer unheated season.