Pool swim season in Imperial Beach, CA
Imperial Beach, CA: how long the pool season really is
An unheated pool in Imperial Beach never reaches 78°F in a normal year. It peaks around 72°F in Aug. The air allows up to 5 swimmable months with a heater (Jun to Oct).
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What each heater buys you in Imperial Beach
| 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 | 5 | Jun to Oct | $0 | $283 |
| Heat pump + cover | 5 | Jun to Oct | $389 | $939 |
| Gas heater + cover | 5 | Jun to Oct | $538 | $963 |
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 Imperial Beach
Solar panels + cover: 5 of 5 possible months for about $283 a year all-in, which works out near $57 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: Imperial Beach Ream Field Nas, 0.2 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Imperial Beach 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 | 67° | 57° | 3.2 | 57° | 63° | – | – |
| Feb | 65° | 57° | 4.1 | 58° | 64° | – | – |
| Mar | 66° | 59° | 5.2 | 60° | 66° | – | – |
| Apr | 67° | 60° | 6.1 | 62° | 68° | – | – |
| May | 68° | 62° | 6.1 | 64° | 70° | – | – |
| Jun | 70° | 65° | 5.9 | 67° | 73° | $137 | $187 |
| Jul | 73° | 69° | 6.1 | 70° | 76° | $72 | $102 |
| Aug | 75° | 70° | 6.1 | 72° | 78° | $28 | $41 |
| Sep | 75° | 69° | 5.4 | 72° | 78° | $40 | $57 |
| Oct | 73° | 65° | 4.3 | 68° | 74° | $112 | $151 |
| Nov | 70° | 60° | 3.4 | 63° | 69° | – | – |
| Dec | 66° | 56° | 2.9 | 58° | 64° | – | – |
Heating costs most in Jun (about $137 with a heat pump, $187 with gas). Sunshine peaks in Apr at 6.1 kWh/m²/day (NASA satellite data, 36.9 km grid cell). Highlighted months are swimmable with no heater.
How Imperial Beach compares with nearby cities
Imperial Beach ranks 301 of 376 California cities for unheated swim months; La Mesa nearby gets a longer season without a heater.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Coronado, CA | 7 mi | 0 | 6 | $412 |
| National City, CA | 7 mi | 0 | 6 | $456 |
| Chula Vista, CA | 7 mi | 0 | 7 | $665 |
| Lemon Grove, CA | 12 mi | 0 | 6 | $456 |
| La Mesa, CA | 15 mi | 2 | 9 | $834 |
| San Diego, CA | 18 mi | 0 | 8 | $699 |