Pool swim season in Katy, TX
When can you swim in an outdoor pool in Katy, TX?
An unheated pool in Katy reaches 78°F in Jun to Oct, about 5 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 Katy pool, side by side
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 5 | Jun to Oct | $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 | $191 | $741 |
| Gas heater + cover | 9 | Mar to Nov | $467 | $892 |
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 Katy
Solar panels + cover: 8 of 9 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: Houston Sugarland Mem, 16.2 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Katy 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 | 68° | 59° | 3.3 | 57° | 63° | – | – |
| Mar | 74° | 65° | 4.5 | 63° | 69° | $100 | $243 |
| Apr | 80° | 70° | 5.3 | 70° | 76° | $36 | $94 |
| May | 87° | 78° | 6.0 | 77° | 83° | – | – |
| Jun | 92° | 83° | 6.3 | 84° | 90° | – | – |
| Jul | 95° | 85° | 6.1 | 87° | 93° | – | – |
| Aug | 94° | 85° | 5.9 | 88° | 94° | – | – |
| Sep | 90° | 81° | 5.0 | 85° | 91° | – | – |
| Oct | 83° | 73° | 4.4 | 78° | 84° | – | – |
| Nov | 74° | 63° | 3.3 | 68° | 74° | $55 | $130 |
| Dec | 67° | 57° | 2.6 | 59° | 65° | – | – |
Heating costs most in Mar (about $100 with a heat pump, $243 with gas). Sunshine peaks in Jun at 6.3 kWh/m²/day (NASA satellite data, 46.2 km grid cell). Highlighted months are swimmable with no heater.
How Katy compares with nearby cities
Katy ranks 34 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 |
|---|---|---|---|---|
| Fulshear, TX | 7 mi | 5 | 9 | $191 |
| Richmond, TX | 15 mi | 5 | 9 | $191 |
| Rosenberg, TX | 17 mi | 5 | 9 | $191 |
| Sugar Land, TX | 18 mi | 5 | 9 | $191 |
| Stafford, TX | 20 mi | 5 | 9 | $191 |
| Bellaire, TX | 24 mi | 4 | 9 | $215 |