Pool swim season in Fredericksburg, TX
When can you swim in an outdoor pool in Fredericksburg, TX?
An unheated pool in Fredericksburg 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 Fredericksburg 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 | $291 | $841 |
| Gas heater + cover | 8 | Mar to Oct | $673 | $1,098 |
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 Fredericksburg
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: Fredericksburg, 2.7 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Fredericksburg 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° | 47° | 3.2 | 48° | 54° | – | – |
| Feb | 64° | 51° | 3.7 | 50° | 56° | – | – |
| Mar | 71° | 58° | 4.7 | 56° | 62° | $179 | $396 |
| Apr | 78° | 66° | 5.6 | 65° | 71° | $87 | $212 |
| May | 84° | 73° | 5.9 | 72° | 78° | $13 | $36 |
| Jun | 90° | 79° | 6.8 | 80° | 86° | – | – |
| Jul | 93° | 82° | 6.8 | 85° | 91° | – | – |
| Aug | 94° | 82° | 6.4 | 86° | 92° | – | – |
| Sep | 88° | 76° | 5.2 | 81° | 87° | – | – |
| Oct | 79° | 67° | 4.4 | 73° | 79° | $12 | $29 |
| Nov | 68° | 56° | 3.3 | 62° | 68° | – | – |
| Dec | 61° | 49° | 2.9 | 52° | 58° | – | – |
Heating costs most in Mar (about $179 with a heat pump, $396 with gas). Sunshine peaks in Jun at 6.8 kWh/m²/day (NASA satellite data, 44.5 km grid cell). Highlighted months are swimmable with no heater.
How Fredericksburg compares with nearby cities
Fredericksburg ranks 232 of 252 Texas cities for unheated swim months; Helotes nearby gets a longer season without a heater.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Kerrville, TX | 22 mi | 4 | 7 | $137 |
| Boerne, TX | 34 mi | 4 | 9 | $364 |
| Fair Oaks Ranch, TX | 39 mi | 4 | 9 | $364 |
| Dripping Springs, TX | 47 mi | 4 | 8 | $216 |
| Helotes, TX | 49 mi | 5 | 9 | $191 |
| Lakeway, TX | 53 mi | 4 | 8 | $220 |