Pool swim season in Tustin, CA
Swim season in Tustin without a heater, and with one
An unheated pool in Tustin reaches 78°F in Aug, about 1 month a year. The air allows up to 9 swimmable months with a heater (Mar to Nov).
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
What each heater buys you in Tustin
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 1 | Aug | $0 | $0 |
| Solar cover only | 5 | Jun to Oct | $0 | $50 |
| Solar panels + cover | 8 | Apr to Nov | $0 | $283 |
| Heat pump + cover | 9 | Mar to Nov | $644 | $1,194 |
| Gas heater + cover | 9 | Mar to Nov | $858 | $1,283 |
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 Tustin
Solar panels + cover: 8 of 9 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 4 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: Santa Ana Fire Station, 3.4 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Tustin 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° | 59° | 3.2 | 59° | 65° | – | – |
| Feb | 69° | 59° | 4.1 | 60° | 66° | – | – |
| Mar | 71° | 62° | 5.4 | 63° | 69° | $220 | $284 |
| Apr | 73° | 64° | 6.5 | 66° | 72° | $151 | $201 |
| May | 75° | 66° | 6.9 | 69° | 75° | $93 | $128 |
| Jun | 78° | 70° | 7.3 | 72° | 78° | $31 | $45 |
| Jul | 83° | 74° | 7.4 | 76° | 82° | – | – |
| Aug | 85° | 75° | 7.1 | 78° | 84° | – | – |
| Sep | 84° | 74° | 6.0 | 77° | 83° | – | – |
| Oct | 79° | 69° | 4.6 | 73° | 79° | $14 | $20 |
| Nov | 74° | 63° | 3.6 | 67° | 73° | $135 | $180 |
| Dec | 68° | 58° | 2.9 | 61° | 67° | – | – |
Heating costs most in Mar (about $220 with a heat pump, $284 with gas). Sunshine peaks in Jul at 7.4 kWh/m²/day (NASA satellite data, 38.6 km grid cell). Highlighted months are swimmable with no heater.
How Tustin compares with nearby cities
Tustin ranks 196 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 |
|---|---|---|---|---|
| Santa Ana, CA | 4 mi | 1 | 9 | $644 |
| Irvine, CA | 4 mi | 1 | 9 | $793 |
| Orange, CA | 5 mi | 1 | 9 | $644 |
| Costa Mesa, CA | 7 mi | 0 | 8 | $547 |
| Newport Beach, CA | 8 mi | 0 | 4 | $192 |
| Fountain Valley, CA | 8 mi | 0 | 8 | $547 |