Pool swim season in Duncan, OK
When can you swim in an outdoor pool in Duncan, OK?
An unheated pool in Duncan 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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Heater options for a Duncan pool, side by side
| 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 | $196 | $746 |
| Gas heater + cover | 7 | Apr to Oct | $399 | $824 |
For a 450 sq ft pool held at 80°F, at OK prices of 13.8¢/kWh electricity and $14/Mcf gas. All-in spreads the purchase over the equipment's life.
The cheapest way to the full season in Duncan
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: Duncan, 1.3 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Duncan 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 | 52° | 40° | 2.9 | 41° | 47° | – | – |
| Feb | 57° | 44° | 3.5 | 43° | 49° | – | – |
| Mar | 65° | 53° | 4.6 | 50° | 56° | – | – |
| Apr | 73° | 61° | 5.6 | 60° | 66° | $120 | $238 |
| May | 81° | 70° | 6.0 | 68° | 74° | $42 | $93 |
| Jun | 89° | 78° | 6.9 | 78° | 84° | – | – |
| Jul | 94° | 83° | 6.9 | 84° | 90° | – | – |
| Aug | 93° | 82° | 6.2 | 86° | 92° | – | – |
| Sep | 86° | 75° | 5.2 | 81° | 87° | – | – |
| Oct | 76° | 63° | 4.0 | 70° | 76° | $34 | $68 |
| Nov | 64° | 51° | 3.1 | 57° | 63° | – | – |
| Dec | 54° | 42° | 2.5 | 46° | 52° | – | – |
Heating costs most in Apr (about $120 with a heat pump, $238 with gas). Sunshine peaks in Jul at 6.9 kWh/m²/day (NASA satellite data, 42.3 km grid cell). Highlighted months are swimmable with no heater.
How Duncan compares with nearby cities
Duncan ranks 17 of 45 Oklahoma cities for unheated swim months; Lawton, Chickasha, Burkburnett nearby get a longer season without a heater.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Lawton, OK | 28 mi | 4 | 7 | $192 |
| Chickasha, OK | 39 mi | 4 | 7 | $178 |
| Burkburnett, TX | 45 mi | 4 | 7 | $171 |
| Wichita Falls, TX | 51 mi | 4 | 7 | $169 |
| Ardmore, OK | 51 mi | 4 | 7 | $126 |
| Newcastle, OK | 56 mi | 3 | 7 | $219 |