Pool swim season in Marysville, CA
Swim season in Marysville without a heater, and with one
An unheated pool in Marysville reaches 78°F in Jun to Sep, about 4 months a year. The air allows up to 7 swimmable months with a heater (Apr to Oct).
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Heater options for a Marysville pool, side by side
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 4 | Jun 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 | $342 | $892 |
| Gas heater + cover | 7 | Apr to Oct | $456 | $881 |
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 Marysville
Solar panels + cover: 6 of 7 possible months for about $283 a year all-in, which works out near $142 for each month it adds.
A solar cover alone adds no swim months here, so if you want a longer season you need a heater (why); still use one at night to hold the heat you pay for. If you get quotes, ask for gas as well as a heat pump: once the purchase price is counted, gas comes out cheaper all-in here (heat pump or gas).
Weather station: Marysville, 0.4 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Marysville 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 | 57° | 49° | 2.1 | 48° | 54° | – | – |
| Feb | 63° | 53° | 3.1 | 51° | 57° | – | – |
| Mar | 68° | 57° | 4.3 | 56° | 62° | – | – |
| Apr | 75° | 62° | 5.9 | 62° | 68° | $230 | $298 |
| May | 83° | 69° | 7.3 | 70° | 76° | $74 | $105 |
| Jun | 92° | 76° | 8.3 | 78° | 84° | – | – |
| Jul | 98° | 81° | 8.3 | 84° | 90° | – | – |
| Aug | 97° | 80° | 7.4 | 85° | 91° | – | – |
| Sep | 91° | 75° | 5.9 | 80° | 86° | – | – |
| Oct | 80° | 66° | 4.1 | 72° | 78° | $38 | $53 |
| Nov | 67° | 55° | 2.6 | 61° | 67° | – | – |
| Dec | 58° | 49° | 1.9 | 51° | 57° | – | – |
Heating costs most in Apr (about $230 with a heat pump, $298 with gas). Sunshine peaks in Jul at 8.3 kWh/m²/day (NASA satellite data, 39.4 km grid cell). Highlighted months are swimmable with no heater.
How Marysville compares with nearby cities
Marysville ranks 34 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 |
|---|---|---|---|---|
| Yuba City, CA | 3 mi | 4 | 7 | $342 |
| Oroville, CA | 24 mi | 3 | 7 | $408 |
| Lincoln, CA | 25 mi | 3 | 6 | $265 |
| Grass Valley, CA | 29 mi | 0 | 6 | $650 |
| Rocklin, CA | 30 mi | 3 | 6 | $265 |
| Roseville, CA | 30 mi | 2 | 7 | $519 |