Pool swim season in St. Augustine, FL
St. Augustine, FL: how long the pool season really is
An unheated pool in St. Augustine reaches 78°F in Jun to Oct, about 5 months a year. The air allows up to 9 swimmable months with a heater (Mar to Nov).
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Heater options for a St. Augustine pool, side by side
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 5 | Jun to Oct | $0 | $0 |
| Solar cover only | 6 | May to Oct | $0 | $50 |
| Solar panels + cover | 9 | Mar to Nov | $0 | $283 |
| Heat pump + cover | 9 | Mar to Nov | $145 | $695 |
| Gas heater + cover | 9 | Mar to Nov | $491 | $916 |
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. Augustine
Solar panels + cover: 9 of 9 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 1 month 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 Augustine Lighthouse, 1.5 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
St. Augustine 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 | 68° | 58° | 3.2 | 59° | 65° | – | – |
| Feb | 70° | 60° | 3.9 | 60° | 66° | – | – |
| Mar | 74° | 65° | 5.1 | 64° | 70° | $86 | $286 |
| Apr | 80° | 70° | 6.1 | 70° | 76° | $30 | $106 |
| May | 85° | 76° | 6.4 | 77° | 83° | – | – |
| Jun | 89° | 80° | 5.8 | 81° | 87° | – | – |
| Jul | 91° | 82° | 5.8 | 84° | 90° | – | – |
| Aug | 90° | 82° | 5.4 | 85° | 91° | – | – |
| Sep | 87° | 80° | 4.9 | 83° | 89° | – | – |
| Oct | 82° | 74° | 4.3 | 79° | 85° | – | – |
| Nov | 75° | 66° | 3.4 | 71° | 77° | $29 | $99 |
| Dec | 69° | 60° | 2.9 | 63° | 69° | – | – |
Heating costs most in Mar (about $86 with a heat pump, $286 with gas). Sunshine peaks in May at 6.4 kWh/m²/day (NASA satellite data, 47.7 km grid cell). Highlighted months are swimmable with no heater.
How St. Augustine compares with nearby cities
St. Augustine ranks 137 of 173 Florida cities for unheated swim months, and no nearby city gets a longer unheated season.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Green Cove Springs, FL | 23 mi | 5 | 9 | $151 |
| Palm Coast, FL | 25 mi | 5 | 9 | $140 |
| Jacksonville Beach, FL | 26 mi | 5 | 9 | $144 |
| Palatka, FL | 28 mi | 4 | 9 | $175 |
| Atlantic Beach, FL | 31 mi | 5 | 9 | $144 |
| Jacksonville, FL | 37 mi | 5 | 9 | $153 |