Pool swim season in Wildwood, MO
Wildwood, MO: how long the pool season really is
An unheated pool in Wildwood reaches 78°F in Jul to Aug, about 2 months a year. The air allows up to 5 swimmable months with a heater (May to Sep).
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Heater options for a Wildwood pool, side by side
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 2 | Jul to Aug | $0 | $0 |
| Solar cover only | 4 | Jun to Sep | $0 | $50 |
| Solar panels + cover | 5 | May to Sep | $0 | $283 |
| Heat pump + cover | 5 | May to Sep | $84 | $634 |
| Gas heater + cover | 5 | May to Sep | $179 | $604 |
For a 450 sq ft pool held at 80°F, at MO prices of 14.3¢/kWh electricity and $15/Mcf gas. All-in spreads the purchase over the equipment's life.
The cheapest way to the full season in Wildwood
Solar cover only: 4 of 5 possible months for about $50 a year all-in, which works out near $25 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 gas as well as a heat pump: once the purchase price is counted, gas comes out cheaper all-in here (heat pump or gas).
Weather station: St Louis Spirit Of St Louis Airport, 5.6 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Wildwood 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 | 41° | 32° | 2.1 | 33° | 39° | – | – |
| Feb | 47° | 36° | 2.8 | 34° | 40° | – | – |
| Mar | 57° | 46° | 3.8 | 42° | 48° | – | – |
| Apr | 68° | 56° | 5.0 | 53° | 59° | – | – |
| May | 77° | 66° | 5.6 | 64° | 70° | $83 | $176 |
| Jun | 86° | 75° | 6.4 | 74° | 80° | $1 | $3 |
| Jul | 90° | 79° | 6.3 | 80° | 86° | – | – |
| Aug | 88° | 77° | 5.6 | 80° | 86° | – | – |
| Sep | 81° | 69° | 4.8 | 75° | 81° | – | – |
| Oct | 70° | 57° | 3.4 | 63° | 69° | – | – |
| Nov | 56° | 45° | 2.4 | 51° | 57° | – | – |
| Dec | 45° | 36° | 1.8 | 39° | 45° | – | – |
Heating costs most in May (about $83 with a heat pump, $176 with gas). Sunshine peaks in Jun at 6.4 kWh/m²/day (NASA satellite data, 16.9 km grid cell). Highlighted months are swimmable with no heater.
How Wildwood compares with nearby cities
Wildwood ranks 43 of 80 Missouri cities for unheated swim months, and no nearby city gets a longer unheated season.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Ellisville, MO | 4 mi | 2 | 5 | $84 |
| Eureka, MO | 6 mi | 2 | 5 | $84 |
| Ballwin, MO | 6 mi | 2 | 5 | $80 |
| Chesterfield, MO | 7 mi | 2 | 5 | $80 |
| Manchester, MO | 9 mi | 2 | 5 | $80 |
| Town and Country, MO | 11 mi | 2 | 5 | $80 |