Pool swim season in Petal, MS
Swim season in Petal without a heater, and with one
An unheated pool in Petal reaches 78°F in Jun to Sep, about 4 months a year. The air allows up to 8 swimmable months with a heater (Mar to Oct).
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Heater options for a Petal pool, side by side
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 4 | Jun to Sep | $0 | $0 |
| Solar cover only | 6 | May to Oct | $0 | $50 |
| Solar panels + cover | 7 | Apr to Oct | $0 | $283 |
| Heat pump + cover | 8 | Mar to Oct | $235 | $785 |
| Gas heater + cover | 8 | Mar to Oct | $503 | $928 |
For a 450 sq ft pool held at 80°F, at MS prices of 15.1¢/kWh electricity and $17/Mcf gas. All-in spreads the purchase over the equipment's life.
The cheapest way to the full season in Petal
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: Hattiesburg Chain Municipal Airport, 5.6 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Petal 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 | 60° | 49° | 2.8 | 50° | 56° | – | – |
| Feb | 65° | 53° | 3.4 | 52° | 58° | – | – |
| Mar | 72° | 60° | 4.5 | 58° | 64° | $150 | $310 |
| Apr | 78° | 66° | 5.6 | 66° | 72° | $73 | $164 |
| May | 85° | 74° | 6.1 | 73° | 79° | $9 | $21 |
| Jun | 90° | 80° | 6.3 | 80° | 86° | – | – |
| Jul | 92° | 82° | 5.9 | 84° | 90° | – | – |
| Aug | 92° | 82° | 5.6 | 85° | 91° | – | – |
| Sep | 88° | 77° | 5.1 | 82° | 88° | – | – |
| Oct | 80° | 67° | 4.2 | 74° | 80° | $3 | $8 |
| Nov | 69° | 57° | 3.3 | 62° | 68° | – | – |
| Dec | 62° | 51° | 2.5 | 54° | 60° | – | – |
Heating costs most in Mar (about $150 with a heat pump, $310 with gas). Sunshine peaks in Jun at 6.3 kWh/m²/day (NASA satellite data, 30.3 km grid cell). Highlighted months are swimmable with no heater.
How Petal compares with nearby cities
Petal ranks 23 of 41 Mississippi cities for unheated swim months, and no nearby city gets a longer unheated season.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Hattiesburg, MS | 6 mi | 4 | 8 | $242 |
| Laurel, MS | 24 mi | 4 | 8 | $276 |
| Bogalusa, LA | 54 mi | 4 | 9 | $265 |
| Picayune, MS | 62 mi | 4 | 9 | $341 |
| Gulfport, MS | 65 mi | 4 | 9 | $269 |
| D'Iberville, MS | 66 mi | 4 | 7 | $53 |