Pool swim season in New Ulm, MN
New Ulm, MN: how long the pool season really is
An unheated pool in New Ulm never reaches 78°F in a normal year. It peaks around 74°F in Jul. The air allows up to 4 swimmable months with a heater (Jun to Sep).
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Heater options for a New Ulm 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 | 4 | Jun to Sep | $134 | $684 |
| Gas heater + cover | 4 | Jun to Sep | $181 | $606 |
For a 450 sq ft pool held at 80°F, at MN prices of 16.4¢/kWh electricity and $11/Mcf gas. All-in spreads the purchase over the equipment's life.
The cheapest way to the full season in New Ulm
Solar panels + cover: 4 of 4 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 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: NEW Ulm 2 SE, 1.3 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
New Ulm 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 | 24° | 15° | 1.9 | 17° | 23° | – | – |
| Feb | 29° | 20° | 3.0 | 18° | 24° | – | – |
| Mar | 41° | 33° | 3.8 | 27° | 33° | – | – |
| Apr | 57° | 47° | 4.7 | 41° | 47° | – | – |
| May | 69° | 59° | 5.4 | 55° | 61° | – | – |
| Jun | 79° | 69° | 6.1 | 67° | 73° | $64 | $90 |
| Jul | 82° | 72° | 6.5 | 74° | 80° | – | – |
| Aug | 80° | 70° | 5.4 | 73° | 79° | $5 | $7 |
| Sep | 73° | 63° | 4.2 | 67° | 73° | $65 | $84 |
| Oct | 60° | 49° | 2.8 | 56° | 62° | – | – |
| Nov | 43° | 34° | 1.8 | 41° | 47° | – | – |
| Dec | 29° | 21° | 1.4 | 26° | 32° | – | – |
Heating costs most in Sep (about $65 with a heat pump, $84 with gas). Sunshine peaks in Jul at 6.5 kWh/m²/day (NASA satellite data, 21.0 km grid cell). Highlighted months are swimmable with no heater.
How New Ulm compares with nearby cities
New Ulm ranks 34 of 103 Minnesota cities for unheated swim months, and no nearby city gets a longer unheated season.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| North Mankato, MN | 23 mi | 0 | 4 | $154 |
| St. Peter, MN | 25 mi | 0 | 4 | $185 |
| Mankato, MN | 26 mi | 0 | 4 | $156 |
| Hutchinson, MN | 40 mi | 0 | 4 | $129 |
| Fairmont, MN | 46 mi | 0 | 4 | $111 |
| Waconia, MN | 50 mi | 0 | 4 | $189 |