Pool swim season in Hartford, CT
When can you swim in an outdoor pool in Hartford, CT?
An unheated pool in Hartford never reaches 78°F in a normal year. It peaks around 77°F in Aug. The air allows up to 5 swimmable months with a heater (May to Sep).
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What each heater buys you in Hartford
| 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 | $410 | $960 |
| Gas heater + cover | 5 | May to Sep | $491 | $916 |
For a 450 sq ft pool held at 80°F, at CT prices of 27.5¢/kWh electricity and $17/Mcf gas. All-in spreads the purchase over the equipment's life.
The cheapest way to the full season in Hartford
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 gas as well as a heat pump: once the purchase price is counted, gas comes out cheaper all-in here (heat pump or gas).
Weather station: Hartford Brainard Field, 2.6 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Hartford 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 | 37° | 29° | 1.9 | 30° | 36° | – | – |
| Feb | 40° | 31° | 2.7 | 29° | 35° | – | – |
| Mar | 48° | 39° | 3.7 | 35° | 41° | – | – |
| Apr | 60° | 50° | 4.9 | 46° | 52° | – | – |
| May | 71° | 61° | 5.5 | 58° | 64° | $275 | $317 |
| Jun | 80° | 70° | 5.9 | 68° | 74° | $89 | $117 |
| Jul | 85° | 75° | 6.0 | 76° | 82° | – | – |
| Aug | 83° | 74° | 5.3 | 77° | 83° | – | – |
| Sep | 76° | 66° | 4.4 | 71° | 77° | $46 | $57 |
| Oct | 64° | 54° | 2.9 | 60° | 66° | – | – |
| Nov | 52° | 43° | 2.1 | 48° | 54° | – | – |
| Dec | 42° | 34° | 1.5 | 37° | 43° | – | – |
Heating costs most in May (about $275 with a heat pump, $317 with gas). Sunshine peaks in Jul at 6.0 kWh/m²/day (NASA satellite data, 33.2 km grid cell). Highlighted months are swimmable with no heater.
How Hartford compares with nearby cities
Hartford ranks 3 of 21 Connecticut cities for unheated swim months, and no nearby city gets a longer unheated season.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| New Britain, CT | 8 mi | 0 | 5 | $410 |
| Bristol, CT | 15 mi | 0 | 5 | $534 |
| Middletown, CT | 15 mi | 0 | 5 | $496 |
| Meriden, CT | 17 mi | 0 | 5 | $496 |
| Agawam Town, MA | 21 mi | 0 | 5 | $601 |
| Waterbury, CT | 23 mi | 0 | 5 | $498 |