Pool swim season in Commerce, CA
Commerce, CA: how long the pool season really is
An unheated pool in Commerce reaches 78°F in Aug to Sep, about 2 months a year. The air allows up to 9 swimmable months with a heater (Mar to Nov).
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Heater options for a Commerce pool, side by side
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 2 | Aug to Sep | $0 | $0 |
| Solar cover only | 5 | Jun to Oct | $0 | $50 |
| Solar panels + cover | 7 | Apr to Oct | $0 | $283 |
| Heat pump + cover | 9 | Mar to Nov | $721 | $1,271 |
| Gas heater + cover | 9 | Mar to Nov | $952 | $1,377 |
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 Commerce
Heat pump + cover: 9 of 9 possible months for about $1,271 a year all-in, which works out near $182 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: San Gabriel Fire Dept, 6.8 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Commerce 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 | 69° | 57° | 3.1 | 57° | 63° | – | – |
| Feb | 68° | 58° | 4.0 | 59° | 65° | – | – |
| Mar | 71° | 61° | 5.2 | 61° | 67° | $252 | $322 |
| Apr | 74° | 63° | 6.3 | 65° | 71° | $168 | $223 |
| May | 76° | 67° | 6.6 | 69° | 75° | $102 | $142 |
| Jun | 81° | 71° | 6.3 | 72° | 78° | $32 | $46 |
| Jul | 86° | 75° | 6.6 | 77° | 83° | – | – |
| Aug | 88° | 77° | 6.3 | 79° | 85° | – | – |
| Sep | 87° | 75° | 5.5 | 78° | 84° | – | – |
| Oct | 81° | 69° | 4.3 | 73° | 79° | $12 | $16 |
| Nov | 74° | 62° | 3.4 | 66° | 72° | $155 | $203 |
| Dec | 68° | 57° | 2.8 | 59° | 65° | – | – |
Heating costs most in Mar (about $252 with a heat pump, $322 with gas). Sunshine peaks in Jul at 6.6 kWh/m²/day (NASA satellite data, 63.8 km grid cell). Highlighted months are swimmable with no heater.
How Commerce compares with nearby cities
Commerce ranks 174 of 376 California cities for unheated swim months; Montebello nearby gets a longer season without a heater.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Bell, CA | 2 mi | 0 | 8 | $487 |
| Bell Gardens, CA | 2 mi | 0 | 8 | $487 |
| Maywood, CA | 2 mi | 0 | 8 | $487 |
| Montebello, CA | 3 mi | 3 | 9 | $650 |
| Cudahy, CA | 3 mi | 0 | 8 | $487 |
| Pico Rivera, CA | 3 mi | 2 | 9 | $721 |