Pool swim season in Friendswood, TX
Swim season in Friendswood without a heater, and with one
An unheated pool in Friendswood 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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What each heater buys you in Friendswood
| 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 | $184 | $734 |
| Gas heater + cover | 9 | Mar to Nov | $451 | $876 |
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 Friendswood
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 Clover Field, 2.6 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Friendswood 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 | 65° | 55° | 2.9 | 56° | 62° | – | – |
| Feb | 68° | 59° | 3.3 | 58° | 64° | – | – |
| Mar | 74° | 65° | 4.5 | 63° | 69° | $98 | $238 |
| Apr | 80° | 71° | 5.3 | 70° | 76° | $35 | $92 |
| May | 86° | 78° | 6.0 | 77° | 83° | – | – |
| Jun | 91° | 83° | 6.3 | 84° | 90° | – | – |
| Jul | 93° | 85° | 6.1 | 87° | 93° | – | – |
| Aug | 94° | 85° | 5.9 | 88° | 94° | – | – |
| Sep | 90° | 81° | 5.0 | 85° | 91° | – | – |
| Oct | 83° | 73° | 4.4 | 79° | 85° | – | – |
| Nov | 73° | 64° | 3.3 | 69° | 75° | $51 | $121 |
| Dec | 66° | 57° | 2.6 | 60° | 66° | – | – |
Heating costs most in Mar (about $98 with a heat pump, $238 with gas). Sunshine peaks in Jun at 6.3 kWh/m²/day (NASA satellite data, 29.0 km grid cell). Highlighted months are swimmable with no heater.
How Friendswood compares with nearby cities
Friendswood ranks 41 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 |
|---|---|---|---|---|
| Webster, TX | 5 mi | 4 | 9 | $203 |
| League City, TX | 6 mi | 4 | 9 | $203 |
| Alvin, TX | 6 mi | 4 | 9 | $235 |
| Pearland, TX | 8 mi | 5 | 9 | $184 |
| Dickinson, TX | 10 mi | 4 | 9 | $203 |
| Manvel, TX | 10 mi | 5 | 9 | $184 |