Pool swim season in Leesburg, VA
Swim season in Leesburg without a heater, and with one
An unheated pool in Leesburg never reaches 78°F in a normal year. It peaks around 78°F in Aug. The air allows up to 5 swimmable months with a heater (May to Sep).
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Heater options for a Leesburg pool, side by side
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 0 | no month | $0 | $0 |
| Solar cover only | 2 | Jul to Aug | $0 | $50 |
| Solar panels + cover | 4 | Jun to Sep | $0 | $283 |
| Heat pump + cover | 5 | May to Sep | $198 | $748 |
| Gas heater + cover | 5 | May to Sep | $391 | $816 |
For a 450 sq ft pool held at 80°F, at VA prices of 16.9¢/kWh electricity and $17/Mcf gas. All-in spreads the purchase over the equipment's life.
The cheapest way to the full season in Leesburg
Solar panels + cover: 4 of 5 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: Purcellville, 8.4 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Leesburg 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 | 41° | 33° | 2.0 | 34° | 40° | – | – |
| Feb | 44° | 35° | 2.8 | 34° | 40° | – | – |
| Mar | 53° | 43° | 3.8 | 40° | 46° | – | – |
| Apr | 65° | 53° | 4.9 | 50° | 56° | – | – |
| May | 73° | 62° | 5.4 | 60° | 66° | $140 | $268 |
| Jun | 81° | 71° | 6.1 | 70° | 76° | $38 | $82 |
| Jul | 86° | 76° | 6.0 | 77° | 83° | – | – |
| Aug | 85° | 74° | 5.3 | 78° | 84° | – | – |
| Sep | 78° | 67° | 4.3 | 72° | 78° | $20 | $41 |
| Oct | 66° | 55° | 3.1 | 61° | 67° | – | – |
| Nov | 55° | 45° | 2.3 | 49° | 55° | – | – |
| Dec | 45° | 37° | 1.7 | 39° | 45° | – | – |
Heating costs most in May (about $140 with a heat pump, $268 with gas). Sunshine peaks in Jun at 6.1 kWh/m²/day (NASA satellite data, 44.1 km grid cell). Highlighted months are swimmable with no heater.
How Leesburg compares with nearby cities
Leesburg ranks 24 of 39 Virginia cities for unheated swim months; Herndon, Gaithersburg, Rockville nearby get a longer season without a heater.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Herndon, VA | 13 mi | 1 | 5 | $145 |
| Gaithersburg, MD | 20 mi | 2 | 5 | $170 |
| Vienna, VA | 22 mi | 0 | 5 | $211 |
| Rockville, MD | 22 mi | 2 | 5 | $170 |
| Fairfax, VA | 22 mi | 0 | 5 | $211 |
| Manassas Park, VA | 24 mi | 2 | 5 | $144 |