Pool swim season in Shasta Lake, CA
Shasta Lake, CA: how long the pool season really is
An unheated pool in Shasta Lake reaches 78°F in Jul to Sep, about 3 months a year. The air allows up to 6 swimmable months with a heater (May to Oct).
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
Heater options for a Shasta Lake pool, side by side
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 3 | Jul to Sep | $0 | $0 |
| Solar cover only | 5 | Jun to Oct | $0 | $50 |
| Solar panels + cover | 6 | May to Oct | $0 | $283 |
| Heat pump + cover | 6 | May to Oct | $159 | $709 |
| Gas heater + cover | 6 | May to Oct | $222 | $647 |
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 Shasta Lake
Solar cover only: 5 of 6 possible months for about $50 a year all-in, which works out near $25 for each month it adds.
Before you pay for any heater, buy a solar cover: on its own it adds 2 months here for about $50 a year (why a cover comes first). 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: Shasta Dam, 3.2 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Shasta Lake 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 | 55° | 48° | 2.0 | 47° | 53° | – | – |
| Feb | 59° | 50° | 3.0 | 49° | 55° | – | – |
| Mar | 63° | 54° | 4.2 | 53° | 59° | – | – |
| Apr | 70° | 59° | 5.8 | 59° | 65° | – | – |
| May | 79° | 67° | 7.1 | 67° | 73° | $129 | $180 |
| Jun | 88° | 76° | 8.1 | 76° | 82° | – | – |
| Jul | 97° | 83° | 8.2 | 85° | 91° | – | – |
| Aug | 96° | 82° | 7.2 | 87° | 93° | – | – |
| Sep | 90° | 77° | 5.8 | 82° | 88° | – | – |
| Oct | 78° | 66° | 4.0 | 72° | 78° | $30 | $42 |
| Nov | 62° | 54° | 2.4 | 60° | 66° | – | – |
| Dec | 54° | 47° | 1.7 | 50° | 56° | – | – |
Heating costs most in May (about $129 with a heat pump, $180 with gas). Sunshine peaks in Jul at 8.2 kWh/m²/day (NASA satellite data, 22.1 km grid cell). Highlighted months are swimmable with no heater.
How Shasta Lake compares with nearby cities
Shasta Lake ranks 38 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 |
|---|---|---|---|---|
| Redding, CA | 7 mi | 3 | 7 | $458 |
| Anderson, CA | 16 mi | 3 | 7 | $458 |
| Red Bluff, CA | 36 mi | 3 | 7 | $448 |
| Chico, CA | 70 mi | 2 | 7 | $512 |
| Arcata, CA | 90 mi | 0 | 0 | $0 |
| Oroville, CA | 92 mi | 3 | 7 | $408 |