Pool swim season in League City, TX
League City, TX: how long the pool season really is
An unheated pool in League City reaches 78°F in Jun to Sep, about 4 months a year. The air allows up to 9 swimmable months with a heater (Mar to Nov).
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Heater options for a League City pool, side by side
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 4 | Jun to Sep | $0 | $0 |
| Solar cover only | 6 | May to Oct | $0 | $50 |
| Solar panels + cover | 8 | Apr to Nov | $0 | $283 |
| Heat pump + cover | 9 | Mar to Nov | $203 | $753 |
| Gas heater + cover | 9 | Mar to Nov | $493 | $918 |
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 League City
Solar panels + cover: 8 of 9 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: Houston Nwso, 2 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
League City 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 | 64° | 55° | 2.9 | 56° | 62° | – | – |
| Feb | 67° | 59° | 3.3 | 57° | 63° | – | – |
| Mar | 73° | 64° | 4.5 | 63° | 69° | $104 | $249 |
| Apr | 78° | 70° | 5.3 | 69° | 75° | $40 | $105 |
| May | 85° | 77° | 6.0 | 76° | 82° | – | – |
| Jun | 90° | 82° | 6.3 | 83° | 89° | – | – |
| Jul | 92° | 84° | 6.1 | 86° | 92° | – | – |
| Aug | 92° | 84° | 5.9 | 87° | 93° | – | – |
| Sep | 88° | 80° | 5.0 | 84° | 90° | – | – |
| Oct | 82° | 72° | 4.4 | 78° | 84° | – | – |
| Nov | 73° | 63° | 3.3 | 68° | 74° | $59 | $139 |
| Dec | 66° | 57° | 2.6 | 59° | 65° | – | – |
Heating costs most in Mar (about $104 with a heat pump, $249 with gas). Sunshine peaks in Jun at 6.3 kWh/m²/day (NASA satellite data, 37.8 km grid cell). Highlighted months are swimmable with no heater.
How League City compares with nearby cities
League City ranks 175 of 252 Texas cities for unheated swim months; Friendswood nearby gets a longer season without a heater.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Webster, TX | 3 mi | 4 | 9 | $203 |
| Dickinson, TX | 4 mi | 4 | 9 | $203 |
| Friendswood, TX | 6 mi | 5 | 9 | $184 |
| Santa Fe, TX | 7 mi | 4 | 9 | $203 |
| Alvin, TX | 8 mi | 4 | 9 | $235 |
| Seabrook, TX | 10 mi | 4 | 9 | $199 |