Pool swim season in Bristol, TN
Swim season in Bristol without a heater, and with one
An unheated pool in Bristol never reaches 78°F in a normal year. It peaks around 78°F in Aug. The air allows up to 6 swimmable months with a heater (May to Oct).
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What each heater buys you in Bristol
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 0 | no month | $0 | $0 |
| Solar cover only | 3 | Jul to Sep | $0 | $50 |
| Solar panels + cover | 5 | May to Sep | $0 | $283 |
| Heat pump + cover | 6 | May to Oct | $201 | $751 |
| Gas heater + cover | 6 | May to Oct | $331 | $756 |
For a 450 sq ft pool held at 80°F, at TN prices of 13.8¢/kWh electricity and $12/Mcf gas. All-in spreads the purchase over the equipment's life.
The cheapest way to the full season in Bristol
Solar panels + cover: 5 of 6 possible months for about $283 a year all-in, which works out near $57 for each month it adds.
Before you pay for any heater, buy a solar cover: on its own it adds 3 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: Bristol Airport, 11.5 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Bristol 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 | 47° | 36° | 2.2 | 37° | 43° | – | – |
| Feb | 51° | 40° | 2.8 | 38° | 44° | – | – |
| Mar | 59° | 47° | 4.0 | 45° | 51° | – | – |
| Apr | 69° | 56° | 5.2 | 54° | 60° | – | – |
| May | 77° | 65° | 5.8 | 63° | 69° | $85 | $146 |
| Jun | 84° | 72° | 6.2 | 72° | 78° | $17 | $32 |
| Jul | 86° | 76° | 5.9 | 77° | 83° | – | – |
| Aug | 86° | 75° | 5.5 | 78° | 84° | – | – |
| Sep | 81° | 69° | 4.7 | 73° | 79° | $6 | $10 |
| Oct | 70° | 57° | 3.6 | 64° | 70° | $93 | $143 |
| Nov | 59° | 46° | 2.7 | 52° | 58° | – | – |
| Dec | 50° | 39° | 2.0 | 42° | 48° | – | – |
Heating costs most in Oct (about $93 with a heat pump, $143 with gas). Sunshine peaks in Jun at 6.2 kWh/m²/day (NASA satellite data, 26.1 km grid cell). Highlighted months are swimmable with no heater.
How Bristol compares with nearby cities
Bristol ranks 62 of 65 Tennessee cities for unheated swim months; Kingsport nearby gets a longer season without a heater.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Bristol, VA | 5 mi | 0 | 5 | $190 |
| Elizabethton, TN | 15 mi | 0 | 6 | $224 |
| Johnson City, TN | 17 mi | 0 | 6 | $224 |
| Kingsport, TN | 18 mi | 1 | 7 | $331 |
| Boone, NC | 39 mi | 0 | 4 | $230 |
| Greeneville, TN | 43 mi | 0 | 6 | $193 |