Pool swim season in St. Joseph, MO

St. Joseph, MO: how long the pool season really is

An unheated pool in St. Joseph 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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What each heater buys you in St. Joseph

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 St. Joseph

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 a heat pump sized to your pool's surface area; here it beats gas all-in (heat pump or gas).

Weather station: St Joseph Rosecrans Mem Airport, 4.7 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.

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

Heating costs most in May (about $99 with a heat pump, $207 with gas). Sunshine peaks in Jun at 6.5 kWh/m²/day (NASA satellite data, 39.9 km grid cell). Highlighted months are swimmable with no heater.

How St. Joseph compares with nearby cities

St. Joseph ranks 58 of 80 Missouri cities for unheated swim months, and no nearby city gets a longer unheated season.