Pool swim season in Henderson, TX
When can you swim in an outdoor pool in Henderson, TX?
An unheated pool in Henderson 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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What each heater buys you in Henderson
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 4 | Jun to Sep | $0 | $0 |
| Solar cover only | 5 | Jun to Oct | $0 | $50 |
| Solar panels + cover | 7 | Apr to Oct | $0 | $283 |
| Heat pump + cover | 7 | Apr to Oct | $125 | $675 |
| Gas heater + cover | 7 | Apr to Oct | $311 | $736 |
For a 450 sq ft pool held at 80°F, at TX prices of 16.0¢/kWh electricity and $19/Mcf gas. All-in spreads the purchase over the equipment's life.
The cheapest way to the full season in Henderson
Solar panels + cover: 7 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: Henderson, 1.8 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Henderson 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 | 59° | 47° | 2.7 | 48° | 54° | – | – |
| Feb | 63° | 51° | 3.1 | 49° | 55° | – | – |
| Mar | 70° | 58° | 4.3 | 56° | 62° | – | – |
| Apr | 77° | 65° | 5.4 | 64° | 70° | $97 | $235 |
| May | 84° | 73° | 5.9 | 72° | 78° | $20 | $55 |
| Jun | 90° | 80° | 6.4 | 80° | 86° | – | – |
| Jul | 94° | 83° | 6.4 | 85° | 91° | – | – |
| Aug | 95° | 83° | 6.0 | 86° | 92° | – | – |
| Sep | 89° | 77° | 5.1 | 82° | 88° | – | – |
| Oct | 80° | 67° | 4.1 | 73° | 79° | $8 | $21 |
| Nov | 68° | 56° | 3.0 | 62° | 68° | – | – |
| Dec | 61° | 49° | 2.5 | 52° | 58° | – | – |
Heating costs most in Apr (about $97 with a heat pump, $235 with gas). Sunshine peaks in Jul at 6.4 kWh/m²/day (NASA satellite data, 47.2 km grid cell). Highlighted months are swimmable with no heater.
How Henderson compares with nearby cities
Henderson ranks 225 of 252 Texas cities for unheated swim months, and no nearby city gets a longer unheated season.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Kilgore, TX | 17 mi | 4 | 7 | $106 |
| Longview, TX | 25 mi | 4 | 8 | $277 |
| Jacksonville, TX | 31 mi | 4 | 8 | $344 |
| Tyler, TX | 32 mi | 4 | 8 | $259 |
| Marshall, TX | 37 mi | 4 | 7 | $161 |
| Nacogdoches, TX | 39 mi | 4 | 7 | $121 |