Pool swim season in Maryville, MO
Swim season in Maryville without a heater, and with one
An unheated pool in Maryville never reaches 78°F in a normal year. It peaks around 78°F in Jul. The air allows up to 5 swimmable months with a heater (May to Sep).
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Heater options for a Maryville pool, side by side
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 0 | no month | $0 | $0 |
| Solar cover only | 2 | Jul to Aug | $0 | $50 |
| Solar panels + cover | 4 | Jun to Sep | $0 | $283 |
| Heat pump + cover | 5 | May to Sep | $166 | $716 |
| Gas heater + cover | 5 | May to Sep | $346 | $771 |
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 Maryville
Solar panels + cover: 4 of 5 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 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: Maryville 2E, 1.9 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Maryville 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 | 34° | 24° | 2.1 | 25° | 31° | – | – |
| Feb | 39° | 28° | 3.0 | 26° | 32° | – | – |
| Mar | 52° | 40° | 3.9 | 35° | 41° | – | – |
| Apr | 63° | 51° | 4.9 | 48° | 54° | – | – |
| May | 73° | 62° | 5.8 | 60° | 66° | $123 | $250 |
| Jun | 83° | 72° | 6.4 | 71° | 77° | $24 | $56 |
| Jul | 87° | 76° | 6.5 | 78° | 84° | – | – |
| Aug | 85° | 74° | 5.6 | 78° | 84° | – | – |
| Sep | 78° | 66° | 4.7 | 72° | 78° | $19 | $40 |
| Oct | 66° | 54° | 3.3 | 60° | 66° | – | – |
| Nov | 51° | 40° | 2.3 | 46° | 52° | – | – |
| Dec | 39° | 29° | 1.8 | 33° | 39° | – | – |
Heating costs most in May (about $123 with a heat pump, $250 with gas). Sunshine peaks in Jul at 6.5 kWh/m²/day (NASA satellite data, 35.9 km grid cell). Highlighted months are swimmable with no heater.
How Maryville compares with nearby cities
Maryville ranks 79 of 80 Missouri cities for unheated swim months; St. Joseph, Atchison, Smithville nearby get a longer season without a heater.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| St. Joseph, MO | 40 mi | 2 | 5 | $115 |
| Atchison, KS | 56 mi | 2 | 5 | $110 |
| Smithville, MO | 67 mi | 2 | 5 | $144 |
| Leavenworth, KS | 71 mi | 2 | 5 | $91 |
| Kearney, MO | 73 mi | 2 | 5 | $125 |
| Lansing, KS | 76 mi | 2 | 5 | $156 |