Pool swim season in Monument, CO
Monument, CO: how long the pool season really is
An unheated pool in Monument never reaches 78°F in a normal year. It peaks around 71°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 Monument 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 | 4 | Jun to Sep | $0 | $283 |
| Heat pump + cover | 4 | Jun to Sep | $284 | $834 |
| Gas heater + cover | 4 | Jun to Sep | $370 | $795 |
For a 450 sq ft pool held at 80°F, at CO prices of 16.8¢/kWh electricity and $11/Mcf gas. All-in spreads the purchase over the equipment's life.
The cheapest way to the full season in Monument
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.
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: Monument 3S, 1.8 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Monument 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 | 43° | 29° | 2.6 | 29° | 35° | – | – |
| Feb | 43° | 29° | 3.5 | 29° | 35° | – | – |
| Mar | 52° | 37° | 4.7 | 35° | 41° | – | – |
| Apr | 57° | 43° | 5.8 | 43° | 49° | – | – |
| May | 67° | 52° | 6.5 | 51° | 57° | – | – |
| Jun | 79° | 63° | 7.2 | 62° | 68° | $121 | $157 |
| Jul | 84° | 68° | 7.0 | 70° | 76° | $40 | $56 |
| Aug | 81° | 66° | 6.3 | 71° | 77° | $32 | $44 |
| Sep | 75° | 60° | 5.4 | 65° | 71° | $91 | $113 |
| Oct | 63° | 47° | 4.0 | 55° | 61° | – | – |
| Nov | 52° | 37° | 2.9 | 42° | 48° | – | – |
| Dec | 43° | 29° | 2.3 | 32° | 38° | – | – |
Heating costs most in Jun (about $121 with a heat pump, $157 with gas). Sunshine peaks in Jun at 7.2 kWh/m²/day (NASA satellite data, 55.8 km grid cell). Highlighted months are swimmable with no heater.
How Monument compares with nearby cities
Monument ranks 52 of 53 Colorado cities for unheated swim months, and no nearby city gets a longer unheated season.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Colorado Springs, CO | 15 mi | 0 | 5 | $315 |
| Castle Rock, CO | 21 mi | 0 | 4 | $177 |
| Castle Pines, CO | 27 mi | 0 | 4 | $177 |
| Fountain, CO | 28 mi | 0 | 5 | $315 |
| Parker, CO | 30 mi | 0 | 5 | $354 |
| Lone Tree, CO | 32 mi | 0 | 4 | $131 |