Pool swim season in St. Marys, GA

When can you swim in an outdoor pool in St. Marys, GA?

An unheated pool in St. Marys reaches 78°F in Jun to Sep, about 4 months a year. The air allows up to 8 swimmable months with a heater (Apr to Nov).

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. Marys

For a 450 sq ft pool held at 80°F, at GA prices of 15.5¢/kWh electricity and $20/Mcf gas. All-in spreads the purchase over the equipment's life.

The cheapest way to the full season in St. Marys

Solar panels + cover: 7 of 8 possible months for about $283 a year all-in, which works out near $94 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: Brunswick 23 S, 7.9 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.

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

Heating costs most in Nov (about $75 with a heat pump, $189 with gas). Sunshine peaks in May at 6.5 kWh/m²/day (NASA satellite data, 29.5 km grid cell). Highlighted months are swimmable with no heater.

How St. Marys compares with nearby cities

St. Marys ranks 21 of 101 Georgia cities for unheated swim months; Jacksonville, Atlantic Beach, Jacksonville Beach nearby get a longer season without a heater.