Pool swim season in The Dalles, OR
Swim season in The Dalles without a heater, and with one
An unheated pool in The Dalles never reaches 78°F in a normal year. It peaks around 78°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 The Dalles
| 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 | $194 | $744 |
| Gas heater + cover | 5 | May to Sep | $411 | $836 |
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 The Dalles
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: Dallesport Airport, 1.6 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
The Dalles 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 | 42° | 37° | 1.3 | 35° | 41° | – | – |
| Feb | 48° | 40° | 2.3 | 38° | 44° | – | – |
| Mar | 57° | 46° | 3.5 | 44° | 50° | – | – |
| Apr | 64° | 53° | 5.1 | 52° | 58° | – | – |
| May | 74° | 61° | 6.3 | 60° | 66° | $127 | $262 |
| Jun | 79° | 67° | 7.1 | 68° | 74° | $49 | $110 |
| Jul | 88° | 75° | 7.7 | 76° | 82° | – | – |
| Aug | 88° | 74° | 6.5 | 78° | 84° | – | – |
| Sep | 80° | 66° | 4.8 | 72° | 78° | $18 | $39 |
| Oct | 66° | 54° | 3.0 | 60° | 66° | – | – |
| Nov | 50° | 43° | 1.6 | 47° | 53° | – | – |
| Dec | 41° | 36° | 1.1 | 38° | 44° | – | – |
Heating costs most in May (about $127 with a heat pump, $262 with gas). Sunshine peaks in Jul at 7.7 kWh/m²/day (NASA satellite data, 29.2 km grid cell). Highlighted months are swimmable with no heater.
How The Dalles compares with nearby cities
The Dalles ranks 5 of 57 Oregon cities for unheated swim months, and no nearby city gets a longer unheated season.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Sandy, OR | 56 mi | 0 | 3 | $206 |
| Washougal, WA | 58 mi | 0 | 4 | $215 |
| Troutdale, OR | 60 mi | 0 | 4 | $231 |
| Camas, WA | 62 mi | 0 | 4 | $175 |
| Fairview, OR | 62 mi | 0 | 4 | $187 |
| Gresham, OR | 63 mi | 0 | 4 | $187 |