Pool swim season in Sheridan, WY
When can you swim in an outdoor pool in Sheridan, WY?
An unheated pool in Sheridan never reaches 78°F in a normal year. It peaks around 73°F in Aug. The air allows up to 4 swimmable months with a heater (Jun to Sep).
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Heater options for a Sheridan pool, side by side
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 0 | no month | $0 | $0 |
| Solar cover only | 1 | Aug | $0 | $50 |
| Solar panels + cover | 4 | Jun to Sep | $0 | $283 |
| Heat pump + cover | 4 | Jun to Sep | $216 | $766 |
| Gas heater + cover | 4 | Jun to Sep | $349 | $774 |
For a 450 sq ft pool held at 80°F, at WY prices of 14.0¢/kWh electricity and $12/Mcf gas. All-in spreads the purchase over the equipment's life.
The cheapest way to the full season in Sheridan
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 1 month 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: Sheridan Airport, 2.5 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Sheridan 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 | 36° | 24° | 1.9 | 23° | 29° | – | – |
| Feb | 38° | 26° | 2.8 | 25° | 31° | – | – |
| Mar | 49° | 36° | 4.0 | 32° | 38° | – | – |
| Apr | 57° | 43° | 5.0 | 42° | 48° | – | – |
| May | 66° | 52° | 5.9 | 51° | 57° | – | – |
| Jun | 77° | 62° | 7.0 | 61° | 67° | $109 | $175 |
| Jul | 88° | 71° | 7.2 | 70° | 76° | $27 | $49 |
| Aug | 87° | 69° | 6.1 | 73° | 79° | $8 | $14 |
| Sep | 76° | 59° | 4.8 | 66° | 72° | $72 | $111 |
| Oct | 60° | 45° | 3.1 | 52° | 58° | – | – |
| Nov | 47° | 33° | 2.1 | 38° | 44° | – | – |
| Dec | 37° | 25° | 1.6 | 28° | 34° | – | – |
Heating costs most in Jun (about $109 with a heat pump, $175 with gas). Sunshine peaks in Jul at 7.2 kWh/m²/day (NASA satellite data, 49.3 km grid cell). Highlighted months are swimmable with no heater.
How Sheridan compares with nearby cities
Sheridan ranks 4 of 11 Wyoming cities for unheated swim months, and no nearby city gets a longer unheated season.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Gillette, WY | 81 mi | 0 | 4 | $166 |
| Billings, MT | 103 mi | 0 | 4 | $142 |
| Cody, WY | 105 mi | 0 | 4 | $212 |
| Casper, WY | 139 mi | 0 | 4 | $151 |
| Riverton, WY | 141 mi | 0 | 4 | $182 |
| Spearfish, SD | 156 mi | 0 | 4 | $198 |