Pool swim season in Round Rock, TX
Swim season in Round Rock without a heater, and with one
An unheated pool in Round Rock reaches 78°F in Jun to Sep, about 4 months a year. The air allows up to 8 swimmable months with a heater (Mar to Oct).
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Heater options for a Round Rock 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 | 7 | Apr to Oct | $0 | $283 |
| Heat pump + cover | 8 | Mar to Oct | $238 | $788 |
| Gas heater + cover | 8 | Mar to Oct | $561 | $986 |
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 Round Rock
Solar panels + cover: 7 of 8 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 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: Austin Great Hills, 9.9 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Round Rock 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 | 60° | 49° | 3.1 | 49° | 55° | – | – |
| Feb | 65° | 53° | 3.5 | 51° | 57° | – | – |
| Mar | 72° | 60° | 4.5 | 58° | 64° | $158 | $359 |
| Apr | 79° | 67° | 5.4 | 66° | 72° | $74 | $185 |
| May | 84° | 74° | 5.9 | 73° | 79° | $6 | $17 |
| Jun | 92° | 81° | 6.7 | 81° | 87° | – | – |
| Jul | 96° | 84° | 6.7 | 87° | 93° | – | – |
| Aug | 96° | 84° | 6.4 | 88° | 94° | – | – |
| Sep | 89° | 78° | 5.2 | 83° | 89° | – | – |
| Oct | 80° | 69° | 4.3 | 75° | 81° | – | – |
| Nov | 69° | 58° | 3.2 | 64° | 70° | – | – |
| Dec | 61° | 50° | 2.7 | 54° | 60° | – | – |
Heating costs most in Mar (about $158 with a heat pump, $359 with gas). Sunshine peaks in Jul at 6.7 kWh/m²/day (NASA satellite data, 15.9 km grid cell). Highlighted months are swimmable with no heater.
How Round Rock compares with nearby cities
Round Rock ranks 135 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 |
|---|---|---|---|---|
| Pflugerville, TX | 7 mi | 4 | 8 | $238 |
| Hutto, TX | 7 mi | 4 | 9 | $350 |
| Cedar Park, TX | 9 mi | 4 | 8 | $238 |
| Georgetown, TX | 10 mi | 4 | 8 | $252 |
| Leander, TX | 12 mi | 4 | 8 | $252 |
| Manor, TX | 13 mi | 4 | 9 | $313 |