Pool swim season in Whittier, CA
Whittier, CA: how long the pool season really is
An unheated pool in Whittier 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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What each heater buys you in Whittier
| 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 | $676 | $1,226 |
| Gas heater + cover | 9 | Mar to Nov | $898 | $1,323 |
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 Whittier
Heat pump + cover: 9 of 9 possible months for about $1,226 a year all-in, which works out near $175 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: Fullerton Municipal Airport, 6.9 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Whittier 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° | 58° | 3.1 | 57° | 63° | – | – |
| Feb | 69° | 59° | 4.0 | 59° | 65° | – | – |
| Mar | 71° | 61° | 5.2 | 62° | 68° | $236 | $304 |
| Apr | 74° | 64° | 6.3 | 66° | 72° | $154 | $206 |
| May | 76° | 67° | 6.6 | 69° | 75° | $92 | $128 |
| Jun | 79° | 71° | 6.3 | 72° | 78° | $33 | $48 |
| Jul | 84° | 75° | 6.6 | 77° | 83° | – | – |
| Aug | 87° | 77° | 6.3 | 79° | 85° | – | – |
| Sep | 85° | 75° | 5.5 | 78° | 84° | – | – |
| Oct | 80° | 69° | 4.3 | 74° | 80° | $10 | $14 |
| Nov | 74° | 62° | 3.4 | 66° | 72° | $151 | $198 |
| Dec | 68° | 57° | 2.8 | 60° | 66° | – | – |
Heating costs most in Mar (about $236 with a heat pump, $304 with gas). Sunshine peaks in Jul at 6.6 kWh/m²/day (NASA satellite data, 68.3 km grid cell). Highlighted months are swimmable with no heater.
How Whittier compares with nearby cities
Whittier ranks 176 of 376 California cities for unheated swim months; La Puente nearby gets a longer season without a heater.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Santa Fe Springs, CA | 3 mi | 2 | 9 | $676 |
| Pico Rivera, CA | 4 mi | 2 | 9 | $721 |
| La Mirada, CA | 5 mi | 2 | 9 | $676 |
| La Habra, CA | 5 mi | 2 | 9 | $635 |
| Norwalk, CA | 5 mi | 2 | 9 | $676 |
| La Puente, CA | 6 mi | 3 | 9 | $631 |