Pool swim season in San Juan Capistrano, CA
Swim season in San Juan Capistrano without a heater, and with one
An unheated pool in San Juan Capistrano never reaches 78°F in a normal year. It peaks around 75°F in Aug. The air allows up to 8 swimmable months with a heater (Apr to Nov).
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What each heater buys you in San Juan Capistrano
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 0 | no month | $0 | $0 |
| Solar cover only | 3 | Jul to Sep | $0 | $50 |
| Solar panels + cover | 7 | Apr to Oct | $0 | $283 |
| Heat pump + cover | 8 | Apr to Nov | $738 | $1,288 |
| Gas heater + cover | 8 | Apr to Nov | $974 | $1,399 |
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 San Juan Capistrano
Solar panels + cover: 7 of 8 possible months for about $283 a year all-in, which works out near $40 for each month it adds.
Before you pay for any heater, buy a solar cover: on its own it adds 3 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: Laguna Beach, 7.9 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
San Juan Capistrano 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 | 68° | 56° | 3.2 | 56° | 62° | – | – |
| Feb | 68° | 56° | 4.1 | 57° | 63° | – | – |
| Mar | 69° | 59° | 5.4 | 60° | 66° | – | – |
| Apr | 73° | 61° | 6.5 | 64° | 70° | $209 | $269 |
| May | 75° | 65° | 6.9 | 67° | 73° | $136 | $183 |
| Jun | 76° | 67° | 7.3 | 70° | 76° | $73 | $102 |
| Jul | 80° | 70° | 7.4 | 73° | 79° | $23 | $32 |
| Aug | 81° | 71° | 7.1 | 75° | 81° | – | – |
| Sep | 81° | 70° | 6.0 | 73° | 79° | $10 | $15 |
| Oct | 77° | 66° | 4.6 | 70° | 76° | $82 | $113 |
| Nov | 72° | 60° | 3.6 | 64° | 70° | $205 | $260 |
| Dec | 67° | 56° | 2.9 | 58° | 64° | – | – |
Heating costs most in Apr (about $209 with a heat pump, $269 with gas). Sunshine peaks in Jul at 7.4 kWh/m²/day (NASA satellite data, 14.3 km grid cell). Highlighted months are swimmable with no heater.
How San Juan Capistrano compares with nearby cities
San Juan Capistrano ranks 264 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 |
|---|---|---|---|---|
| Dana Point, CA | 3 mi | 0 | 8 | $738 |
| Laguna Niguel, CA | 3 mi | 0 | 8 | $738 |
| San Clemente, CA | 4 mi | 0 | 8 | $738 |
| Laguna Hills, CA | 7 mi | 0 | 8 | $738 |
| Laguna Beach, CA | 7 mi | 0 | 8 | $738 |
| Aliso Viejo, CA | 7 mi | 0 | 8 | $738 |