Pool swim season in Grain Valley, MO

Swim season in Grain Valley without a heater, and with one

An unheated pool in Grain Valley 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).

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 Grain Valley

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 Grain Valley

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: Lees Summit Municipal Airport, 9.2 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.

Grain Valley month by month: air, sun and pool water

Heating costs most in May (about $89 with a heat pump, $188 with gas). Sunshine peaks in Jun at 6.5 kWh/m²/day (NASA satellite data, 59.2 km grid cell). Highlighted months are swimmable with no heater.

How Grain Valley compares with nearby cities

Grain Valley ranks 34 of 80 Missouri cities for unheated swim months, and no nearby city gets a longer unheated season.