Pool swim season in Oroville, CA
Swim season in Oroville without a heater, and with one
An unheated pool in Oroville reaches 78°F in Jul to Sep, about 3 months a year. The air allows up to 7 swimmable months with a heater (Apr to Oct).
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What each heater buys you in Oroville
| 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 | 6 | May to Oct | $0 | $283 |
| Heat pump + cover | 7 | Apr to Oct | $408 | $958 |
| Gas heater + cover | 7 | Apr to Oct | $540 | $965 |
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 Oroville
Solar panels + cover: 6 of 7 possible months for about $283 a year all-in, which works out near $94 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: Oroville, 1.6 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Oroville 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° | 2.1 | 48° | 54° | – | – |
| Feb | 62° | 52° | 3.1 | 51° | 57° | – | – |
| Mar | 68° | 57° | 4.3 | 56° | 62° | – | – |
| Apr | 74° | 61° | 5.9 | 62° | 68° | $246 | $315 |
| May | 82° | 68° | 7.3 | 69° | 75° | $93 | $131 |
| Jun | 91° | 75° | 8.3 | 77° | 83° | – | – |
| Jul | 97° | 80° | 8.3 | 83° | 89° | – | – |
| Aug | 96° | 78° | 7.4 | 84° | 90° | – | – |
| Sep | 90° | 73° | 5.9 | 79° | 85° | – | – |
| Oct | 79° | 65° | 4.1 | 70° | 76° | $69 | $94 |
| Nov | 66° | 55° | 2.6 | 60° | 66° | – | – |
| Dec | 58° | 49° | 1.9 | 51° | 57° | – | – |
Heating costs most in Apr (about $246 with a heat pump, $315 with gas). Sunshine peaks in Jul at 8.3 kWh/m²/day (NASA satellite data, 5.2 km grid cell). Highlighted months are swimmable with no heater.
How Oroville compares with nearby cities
Oroville ranks 84 of 376 California cities for unheated swim months; Marysville, Yuba City nearby get a longer season without a heater.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Chico, CA | 23 mi | 2 | 7 | $512 |
| Marysville, CA | 24 mi | 4 | 7 | $342 |
| Yuba City, CA | 26 mi | 4 | 7 | $342 |
| Grass Valley, CA | 33 mi | 0 | 6 | $650 |
| Lincoln, CA | 45 mi | 3 | 6 | $265 |
| Auburn, CA | 49 mi | 3 | 6 | $265 |