Pool swim season in Hudson, WI
Swim season in Hudson without a heater, and with one
An unheated pool in Hudson never reaches 78°F in a normal year. It peaks around 76°F in Aug. The air allows up to 5 swimmable months with a heater (May to Sep).
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
Heater options for a Hudson 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 | $285 | $835 |
| Gas heater + cover | 5 | May to Sep | $317 | $742 |
For a 450 sq ft pool held at 80°F, at WI prices of 19.1¢/kWh electricity and $11/Mcf gas. All-in spreads the purchase over the equipment's life.
The cheapest way to the full season in Hudson
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 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: Stillwater 1 SE, 6.3 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Hudson 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 | 27° | 18° | 1.8 | 20° | 26° | – | – |
| Feb | 32° | 23° | 2.9 | 20° | 26° | – | – |
| Mar | 45° | 35° | 3.8 | 30° | 36° | – | – |
| Apr | 60° | 49° | 4.7 | 43° | 49° | – | – |
| May | 73° | 61° | 5.4 | 57° | 63° | $193 | $207 |
| Jun | 81° | 71° | 6.0 | 69° | 75° | $52 | $64 |
| Jul | 85° | 75° | 6.3 | 76° | 82° | – | – |
| Aug | 84° | 73° | 5.3 | 76° | 82° | – | – |
| Sep | 76° | 65° | 4.1 | 70° | 76° | $40 | $46 |
| Oct | 62° | 52° | 2.7 | 58° | 64° | – | – |
| Nov | 45° | 37° | 1.7 | 43° | 49° | – | – |
| Dec | 32° | 24° | 1.3 | 29° | 35° | – | – |
Heating costs most in May (about $193 with a heat pump, $207 with gas). Sunshine peaks in Jul at 6.3 kWh/m²/day (NASA satellite data, 54.7 km grid cell). Highlighted months are swimmable with no heater.
How Hudson compares with nearby cities
Hudson ranks 2 of 98 Wisconsin cities for unheated swim months, and no nearby city gets a longer unheated season.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Stillwater, MN | 8 mi | 0 | 4 | $200 |
| River Falls, WI | 9 mi | 0 | 4 | $281 |
| Lake Elmo, MN | 9 mi | 0 | 4 | $196 |
| Woodbury, MN | 10 mi | 0 | 4 | $141 |
| Oakdale, MN | 12 mi | 0 | 4 | $141 |
| North St. Paul, MN | 14 mi | 0 | 4 | $144 |