Pool swim season in Grand Forks, ND
Grand Forks, ND: how long the pool season really is
An unheated pool in Grand Forks never reaches 78°F in a normal year. It peaks around 71°F in Aug. The air allows up to 3 swimmable months with a heater (Jun to Aug).
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Heater options for a Grand Forks pool, side by side
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 0 | no month | $0 | $0 |
| Solar cover only | 0 | no month | $0 | $50 |
| Solar panels + cover | 3 | Jun to Aug | $0 | $283 |
| Heat pump + cover | 3 | Jun to Aug | $119 | $669 |
| Gas heater + cover | 3 | Jun to Aug | $186 | $611 |
For a 450 sq ft pool held at 80°F, at ND prices of 12.5¢/kWh electricity and $10/Mcf gas. All-in spreads the purchase over the equipment's life.
The cheapest way to the full season in Grand Forks
Solar panels + cover: 3 of 3 possible months for about $283 a year all-in, which works out near $94 for each month it adds.
A solar cover alone adds no swim months here, so if you want a longer season you need a heater (why); still use one at night to hold the heat you pay for. 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: Grand Forks Univ (Nws), 0.5 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Grand Forks 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 | 15° | 7° | 1.7 | 9° | 15° | – | – |
| Feb | 20° | 11° | 3.0 | 9° | 15° | – | – |
| Mar | 34° | 25° | 4.0 | 19° | 25° | – | – |
| Apr | 52° | 42° | 4.9 | 35° | 41° | – | – |
| May | 67° | 55° | 5.6 | 51° | 57° | – | – |
| Jun | 76° | 65° | 6.1 | 63° | 69° | $77 | $118 |
| Jul | 80° | 70° | 6.4 | 71° | 77° | $21 | $35 |
| Aug | 79° | 68° | 5.4 | 71° | 77° | $21 | $33 |
| Sep | 70° | 59° | 3.9 | 64° | 70° | – | – |
| Oct | 53° | 44° | 2.5 | 51° | 57° | – | – |
| Nov | 35° | 27° | 1.5 | 34° | 40° | – | – |
| Dec | 21° | 13° | 1.2 | 19° | 25° | – | – |
Heating costs most in Jun (about $77 with a heat pump, $118 with gas). Sunshine peaks in Jul at 6.4 kWh/m²/day (NASA satellite data, 55.9 km grid cell). Highlighted months are swimmable with no heater.
How Grand Forks compares with nearby cities
Grand Forks ranks 9 of 9 North Dakota cities for unheated swim months, and no nearby city gets a longer unheated season.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Fargo, ND | 74 mi | 0 | 4 | $165 |
| West Fargo, ND | 74 mi | 0 | 4 | $165 |
| Moorhead, MN | 75 mi | 0 | 4 | $188 |
| Detroit Lakes, MN | 96 mi | 0 | 3 | $191 |
| Jamestown, ND | 103 mi | 0 | 4 | $186 |
| Bemidji, MN | 107 mi | 0 | 3 | $199 |