Pool swim season in Stockton, CA
Stockton, CA: how long the pool season really is
An unheated pool in Stockton reaches 78°F in Jul to Sep, about 3 months a year. The air allows up to 8 swimmable months with a heater (Mar to Oct).
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
What each heater buys you in Stockton
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 3 | Jul to Sep | $0 | $0 |
| Solar cover only | 4 | Jun to Sep | $0 | $50 |
| Solar panels + cover | 7 | Apr to Oct | $0 | $283 |
| Heat pump + cover | 8 | Mar to Oct | $671 | $1,221 |
| Gas heater + cover | 8 | Mar to Oct | $859 | $1,284 |
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 Stockton
Solar panels + cover: 7 of 8 possible months for about $283 a year all-in, which works out near $71 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: Stockton Fire Station 4, 1.7 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Stockton 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 | 58° | 49° | 2.4 | 48° | 54° | – | – |
| Feb | 65° | 53° | 3.5 | 52° | 58° | – | – |
| Mar | 70° | 58° | 4.8 | 57° | 63° | $347 | $425 |
| Apr | 75° | 62° | 6.2 | 63° | 69° | $211 | $275 |
| May | 83° | 69° | 7.5 | 70° | 76° | $73 | $104 |
| Jun | 91° | 74° | 8.3 | 77° | 83° | – | – |
| Jul | 95° | 78° | 8.2 | 81° | 87° | – | – |
| Aug | 95° | 77° | 7.4 | 82° | 88° | – | – |
| Sep | 92° | 75° | 6.0 | 79° | 85° | – | – |
| Oct | 82° | 66° | 4.4 | 72° | 78° | $40 | $55 |
| Nov | 69° | 56° | 2.9 | 61° | 67° | – | – |
| Dec | 59° | 49° | 2.2 | 52° | 58° | – | – |
Heating costs most in Mar (about $347 with a heat pump, $425 with gas). Sunshine peaks in Jun at 8.3 kWh/m²/day (NASA satellite data, 55.6 km grid cell). Highlighted months are swimmable with no heater.
How Stockton compares with nearby cities
Stockton ranks 111 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 |
|---|---|---|---|---|
| Lodi, CA | 10 mi | 2 | 7 | $426 |
| Lathrop, CA | 12 mi | 3 | 7 | $390 |
| Manteca, CA | 13 mi | 3 | 7 | $390 |
| Ripon, CA | 19 mi | 3 | 7 | $390 |
| Tracy, CA | 19 mi | 2 | 7 | $522 |
| Galt, CA | 20 mi | 2 | 7 | $426 |