Pool swim season in Rancho Mirage, CA
When can you swim in an outdoor pool in Rancho Mirage, CA?
An unheated pool in Rancho Mirage reaches 78°F in May to Oct, about 6 months a year. The air allows up to 11 swimmable months with a heater (Jan to Nov).
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Heater options for a Rancho Mirage pool, side by side
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 6 | May to Oct | $0 | $0 |
| Solar cover only | 8 | Apr to Nov | $0 | $50 |
| Solar panels + cover | 9 | Mar to Nov | $0 | $283 |
| Heat pump + cover | 11 | Jan to Nov | $705 | $1,255 |
| Gas heater + cover | 11 | Jan to Nov | $911 | $1,336 |
For a 450 sq ft pool held at 80°F, at CA prices of 32.6¢/kWh electricity and $22/Mcf gas. All-in spreads the purchase over the equipment's life.
The cheapest way to the full season in Rancho Mirage
Heat pump + cover: 11 of 11 possible months for about $1,255 a year all-in, which works out near $251 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 a heat pump sized to your pool's surface area; here it beats gas all-in (heat pump or gas).
Weather station: Palm Springs, 5.9 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Rancho Mirage 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 | 71° | 59° | 3.4 | 59° | 65° | $313 | $390 |
| Feb | 74° | 62° | 4.3 | 62° | 68° | $244 | $316 |
| Mar | 81° | 68° | 5.7 | 67° | 73° | $122 | $170 |
| Apr | 87° | 73° | 7.0 | 74° | 80° | – | – |
| May | 95° | 80° | 7.9 | 82° | 88° | – | – |
| Jun | 104° | 88° | 8.4 | 90° | 96° | – | – |
| Jul | 109° | 94° | 7.8 | 96° | 102° | – | – |
| Aug | 108° | 94° | 7.3 | 98° | 104° | – | – |
| Sep | 102° | 88° | 6.3 | 94° | 100° | – | – |
| Oct | 91° | 78° | 5.0 | 85° | 91° | – | – |
| Nov | 79° | 66° | 3.7 | 73° | 79° | $26 | $35 |
| Dec | 69° | 58° | 3.0 | 62° | 68° | – | – |
Heating costs most in Jan (about $313 with a heat pump, $390 with gas). Sunshine peaks in Jun at 8.4 kWh/m²/day (NASA satellite data, 30.0 km grid cell). Highlighted months are swimmable with no heater.
How Rancho Mirage compares with nearby cities
Rancho Mirage ranks 2 of 376 California cities for unheated swim months, and no nearby city gets a longer unheated season.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Palm Desert, CA | 4 mi | 6 | 11 | $701 |
| Cathedral City, CA | 5 mi | 6 | 11 | $705 |
| Palm Springs, CA | 7 mi | 6 | 11 | $731 |
| Indio, CA | 11 mi | 6 | 11 | $701 |
| La Quinta, CA | 12 mi | 6 | 11 | $701 |
| Desert Hot Springs, CA | 15 mi | 3 | 7 | $346 |