Pool swim season in Madison, AL
Madison, AL: how long the pool season really is
An unheated pool in Madison reaches 78°F in Jun to Sep, about 4 months a year. The air allows up to 7 swimmable months with a heater (Apr to Oct).
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Heater options for a Madison pool, side by side
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 4 | Jun to Sep | $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 | $197 | $747 |
| Gas heater + cover | 7 | Apr to Oct | $418 | $843 |
For a 450 sq ft pool held at 80°F, at AL prices of 16.5¢/kWh electricity and $18/Mcf gas. All-in spreads the purchase over the equipment's life.
The cheapest way to the full season in Madison
Solar panels + cover: 6 of 7 possible months for about $283 a year all-in, which works out near $142 for each month it adds.
A solar cover alone adds no swim months here, so if you want a longer season you need a heater (why); still use one at night to hold the heat you pay for. 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: Huntsville Intnl Airport, 4.8 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Madison 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 | 52° | 43° | 2.5 | 44° | 50° | – | – |
| Feb | 57° | 47° | 3.0 | 45° | 51° | – | – |
| Mar | 66° | 54° | 4.2 | 52° | 58° | – | – |
| Apr | 75° | 63° | 5.5 | 61° | 67° | $127 | $263 |
| May | 83° | 71° | 6.0 | 70° | 76° | $34 | $79 |
| Jun | 89° | 79° | 6.3 | 78° | 84° | – | – |
| Jul | 92° | 81° | 6.1 | 83° | 89° | – | – |
| Aug | 91° | 81° | 5.6 | 84° | 90° | – | – |
| Sep | 87° | 75° | 4.9 | 80° | 86° | – | – |
| Oct | 76° | 64° | 3.9 | 70° | 76° | $36 | $76 |
| Nov | 64° | 53° | 2.9 | 58° | 64° | – | – |
| Dec | 55° | 46° | 2.2 | 48° | 54° | – | – |
Heating costs most in Apr (about $127 with a heat pump, $263 with gas). Sunshine peaks in Jun at 6.3 kWh/m²/day (NASA satellite data, 33.5 km grid cell). Highlighted months are swimmable with no heater.
How Madison compares with nearby cities
Madison ranks 29 of 66 Alabama cities for unheated swim months, and no nearby city gets a longer unheated season.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Huntsville, AL | 5 mi | 4 | 7 | $197 |
| Athens, AL | 12 mi | 3 | 7 | $211 |
| Decatur, AL | 16 mi | 2 | 7 | $245 |
| Hartselle, AL | 21 mi | 2 | 7 | $245 |
| Cullman, AL | 37 mi | 3 | 7 | $245 |
| Scottsboro, AL | 41 mi | 2 | 7 | $309 |