Pool swim season in Greeneville, TN
When can you swim in an outdoor pool in Greeneville, TN?
An unheated pool in Greeneville 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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Heater options for a Greeneville pool, side by side
| 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 | $193 | $743 |
| Gas heater + cover | 6 | May to Oct | $320 | $745 |
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 Greeneville
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: Greeneville Experiment Station, 4.5 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Greeneville 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 | 48° | 37° | 2.2 | 37° | 43° | – | – |
| Feb | 52° | 40° | 2.8 | 38° | 44° | – | – |
| Mar | 60° | 47° | 4.0 | 45° | 51° | – | – |
| Apr | 70° | 56° | 5.2 | 54° | 60° | – | – |
| May | 78° | 65° | 5.8 | 63° | 69° | $87 | $149 |
| Jun | 84° | 73° | 6.2 | 72° | 78° | $16 | $30 |
| Jul | 87° | 76° | 5.9 | 77° | 83° | – | – |
| Aug | 87° | 75° | 5.5 | 78° | 84° | – | – |
| Sep | 82° | 69° | 4.7 | 74° | 80° | $2 | $4 |
| Oct | 72° | 58° | 3.6 | 64° | 70° | $88 | $137 |
| Nov | 60° | 47° | 2.7 | 52° | 58° | – | – |
| Dec | 51° | 40° | 2.0 | 42° | 48° | – | – |
Heating costs most in Oct (about $88 with a heat pump, $137 with gas). Sunshine peaks in Jun at 6.2 kWh/m²/day (NASA satellite data, 46.7 km grid cell). Highlighted months are swimmable with no heater.
How Greeneville compares with nearby cities
Greeneville ranks 59 of 65 Tennessee cities for unheated swim months; Morristown, Kingsport nearby get a longer season without a heater.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Morristown, TN | 27 mi | 1 | 6 | $170 |
| Johnson City, TN | 27 mi | 0 | 6 | $224 |
| Kingsport, TN | 29 mi | 1 | 7 | $331 |
| Elizabethton, TN | 35 mi | 0 | 6 | $224 |
| Bristol, TN | 43 mi | 0 | 6 | $201 |
| Asheville, NC | 44 mi | 0 | 5 | $111 |