Pool swim season in Pendleton, OR
Pendleton, OR: how long the pool season really is
An unheated pool in Pendleton never reaches 78°F in a normal year. It peaks around 76°F in Aug. The air allows up to 5 swimmable months with a heater (May to Sep).
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What each heater buys you in Pendleton
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 0 | no month | $0 | $0 |
| Solar cover only | 2 | Jul to Aug | $0 | $50 |
| Solar panels + cover | 4 | Jun to Sep | $0 | $283 |
| Heat pump + cover | 5 | May to Sep | $259 | $809 |
| Gas heater + cover | 5 | May to Sep | $535 | $960 |
For a 450 sq ft pool held at 80°F, at OR prices of 15.5¢/kWh electricity and $17/Mcf gas. All-in spreads the purchase over the equipment's life.
The cheapest way to the full season in Pendleton
Solar panels + cover: 4 of 5 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 2 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: Pendleton Dwtn, 1.2 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Pendleton 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 | 45° | 36° | 1.4 | 34° | 40° | – | – |
| Feb | 49° | 39° | 2.3 | 37° | 43° | – | – |
| Mar | 58° | 46° | 3.5 | 43° | 49° | – | – |
| Apr | 65° | 52° | 5.1 | 51° | 57° | – | – |
| May | 73° | 59° | 6.2 | 59° | 65° | $150 | $299 |
| Jun | 80° | 65° | 7.1 | 66° | 72° | $68 | $149 |
| Jul | 90° | 73° | 7.7 | 74° | 80° | – | – |
| Aug | 90° | 72° | 6.5 | 76° | 82° | – | – |
| Sep | 80° | 63° | 4.8 | 70° | 76° | $41 | $87 |
| Oct | 67° | 52° | 3.0 | 58° | 64° | – | – |
| Nov | 52° | 42° | 1.6 | 46° | 52° | – | – |
| Dec | 44° | 36° | 1.1 | 37° | 43° | – | – |
Heating costs most in May (about $150 with a heat pump, $299 with gas). Sunshine peaks in Jul at 7.7 kWh/m²/day (NASA satellite data, 31.6 km grid cell). Highlighted months are swimmable with no heater.
How Pendleton compares with nearby cities
Pendleton ranks 7 of 57 Oregon cities for unheated swim months; Hermiston, Walla Walla, Kennewick nearby get a longer season without a heater.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Hermiston, OR | 25 mi | 1 | 5 | $202 |
| Walla Walla, WA | 36 mi | 1 | 5 | $187 |
| Kennewick, WA | 40 mi | 1 | 5 | $141 |
| La Grande, OR | 43 mi | 0 | 4 | $200 |
| Pasco, WA | 43 mi | 0 | 5 | $190 |
| Richland, WA | 48 mi | 0 | 5 | $187 |