Pool swim season in Irvine, CA
When can you swim in an outdoor pool in Irvine, CA?
An unheated pool in Irvine reaches 78°F in Aug, about 1 month 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 Irvine
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 1 | Aug | $0 | $0 |
| Solar cover only | 4 | Jul to Oct | $0 | $50 |
| Solar panels + cover | 7 | Apr to Oct | $0 | $283 |
| Heat pump + cover | 9 | Mar to Nov | $793 | $1,343 |
| Gas heater + cover | 9 | Mar to Nov | $1,033 | $1,458 |
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 Irvine
Heat pump + cover: 9 of 9 possible months for about $1,343 a year all-in, which works out near $168 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: Tustin Irvine Rch, 1.9 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Irvine 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 | 69° | 57° | 4.1 | 57° | 63° | – | – |
| Mar | 72° | 60° | 5.4 | 61° | 67° | $268 | $338 |
| Apr | 74° | 62° | 6.5 | 64° | 70° | $189 | $246 |
| May | 77° | 66° | 6.9 | 68° | 74° | $118 | $161 |
| Jun | 80° | 69° | 7.3 | 72° | 78° | $44 | $62 |
| Jul | 85° | 73° | 7.4 | 76° | 82° | – | – |
| Aug | 87° | 75° | 7.1 | 78° | 84° | – | – |
| Sep | 87° | 74° | 6.0 | 78° | 84° | – | – |
| Oct | 84° | 69° | 4.6 | 73° | 79° | $15 | $21 |
| Nov | 76° | 62° | 3.6 | 66° | 72° | $159 | $205 |
| Dec | 70° | 56° | 2.9 | 59° | 65° | – | – |
Heating costs most in Mar (about $268 with a heat pump, $338 with gas). Sunshine peaks in Jul at 7.4 kWh/m²/day (NASA satellite data, 32.0 km grid cell). Highlighted months are swimmable with no heater.
How Irvine compares with nearby cities
Irvine ranks 197 of 376 California cities for unheated swim months; Lake Forest nearby gets a longer season without a heater.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Tustin, CA | 4 mi | 1 | 9 | $644 |
| Laguna Woods, CA | 5 mi | 0 | 8 | $738 |
| Lake Forest, CA | 6 mi | 2 | 10 | $857 |
| Newport Beach, CA | 6 mi | 0 | 4 | $192 |
| Aliso Viejo, CA | 7 mi | 0 | 8 | $738 |
| Laguna Hills, CA | 7 mi | 0 | 8 | $738 |