Pool swim season in Williamsburg, VA
Swim season in Williamsburg without a heater, and with one
An unheated pool in Williamsburg reaches 78°F in Jul to Aug, about 2 months a year. The air allows up to 7 swimmable months with a heater (Apr to Oct).
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What each heater buys you in Williamsburg
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 2 | Jul to Aug | $0 | $0 |
| Solar cover only | 4 | Jun to Sep | $0 | $50 |
| Solar panels + cover | 6 | May to Oct | $0 | $283 |
| Heat pump + cover | 7 | Apr to Oct | $339 | $889 |
| Gas heater + cover | 7 | Apr to Oct | $640 | $1,065 |
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 Williamsburg
Solar panels + cover: 6 of 7 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: Williamsburg 2 N, 2.2 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Williamsburg 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 | 49° | 40° | 2.3 | 41° | 47° | – | – |
| Feb | 52° | 42° | 3.1 | 41° | 47° | – | – |
| Mar | 60° | 49° | 4.2 | 47° | 53° | – | – |
| Apr | 70° | 59° | 5.3 | 56° | 62° | $189 | $345 |
| May | 77° | 67° | 5.9 | 66° | 72° | $77 | $157 |
| Jun | 84° | 75° | 6.4 | 74° | 80° | – | – |
| Jul | 89° | 79° | 6.2 | 80° | 86° | – | – |
| Aug | 87° | 78° | 5.5 | 81° | 87° | – | – |
| Sep | 81° | 72° | 4.5 | 76° | 82° | – | – |
| Oct | 71° | 61° | 3.5 | 67° | 73° | $73 | $138 |
| Nov | 61° | 51° | 2.6 | 56° | 62° | – | – |
| Dec | 53° | 43° | 2.0 | 46° | 52° | – | – |
Heating costs most in Apr (about $189 with a heat pump, $345 with gas). Sunshine peaks in Jun at 6.4 kWh/m²/day (NASA satellite data, 31.5 km grid cell). Highlighted months are swimmable with no heater.
How Williamsburg compares with nearby cities
Williamsburg ranks 7 of 39 Virginia cities for unheated swim months, and no nearby city gets a longer unheated season.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Newport News, VA | 17 mi | 2 | 6 | $154 |
| Poquoson, VA | 24 mi | 2 | 5 | $83 |
| Hampton, VA | 27 mi | 2 | 5 | $83 |
| Hopewell, VA | 33 mi | 2 | 7 | $294 |
| Portsmouth, VA | 34 mi | 2 | 6 | $114 |
| Norfolk, VA | 35 mi | 2 | 6 | $114 |