Pool swim season in Calexico, CA
Calexico, CA: how long the pool season really is
An unheated pool in Calexico 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 Calexico pool, side by side
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 6 | May to Oct | $0 | $0 |
| Solar cover only | 7 | Apr to Oct | $0 | $50 |
| Solar panels + cover | 9 | Mar to Nov | $0 | $283 |
| Heat pump + cover | 11 | Jan to Nov | $836 | $1,386 |
| Gas heater + cover | 11 | Jan to Nov | $1,064 | $1,489 |
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 Calexico
Heat pump + cover: 11 of 11 possible months for about $1,386 a year all-in, which works out near $277 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: El Centro 2 SSW, 6.9 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Calexico 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° | 57° | 3.6 | 57° | 63° | $351 | $427 |
| Feb | 74° | 60° | 4.5 | 60° | 66° | $275 | $350 |
| Mar | 80° | 66° | 6.0 | 66° | 72° | $148 | $202 |
| Apr | 86° | 72° | 7.3 | 73° | 79° | $18 | $26 |
| May | 94° | 79° | 8.1 | 80° | 86° | – | – |
| Jun | 103° | 87° | 8.4 | 88° | 94° | – | – |
| Jul | 107° | 93° | 7.7 | 94° | 100° | – | – |
| Aug | 107° | 93° | 7.2 | 97° | 103° | – | – |
| Sep | 102° | 88° | 6.3 | 94° | 100° | – | – |
| Oct | 92° | 77° | 5.1 | 84° | 90° | – | – |
| Nov | 79° | 65° | 3.9 | 72° | 78° | $44 | $59 |
| Dec | 70° | 56° | 3.2 | 61° | 67° | – | – |
Heating costs most in Jan (about $351 with a heat pump, $427 with gas). Sunshine peaks in Jun at 8.4 kWh/m²/day (NASA satellite data, 20.6 km grid cell). Highlighted months are swimmable with no heater.
How Calexico compares with nearby cities
Calexico ranks 10 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 |
|---|---|---|---|---|
| El Centro, CA | 8 mi | 6 | 11 | $836 |
| Imperial, CA | 12 mi | 6 | 11 | $951 |
| Brawley, CA | 20 mi | 6 | 12 | $1,201 |
| Somerton, AZ | 47 mi | 6 | 10 | $174 |
| San Luis, AZ | 47 mi | 6 | 10 | $174 |
| Yuma, AZ | 58 mi | 6 | 10 | $174 |