Pool swim season in New Haven, CT
When can you swim in an outdoor pool in New Haven, CT?
An unheated pool in New Haven never reaches 78°F in a normal year. It peaks around 76°F in Aug. The air allows up to 4 swimmable months with a heater (Jun to Sep).
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What each heater buys you in New Haven
| 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 | 4 | Jun to Sep | $172 | $722 |
| Gas heater + cover | 4 | Jun to Sep | $218 | $643 |
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 New Haven
Solar panels + cover: 4 of 4 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: NEW Haven Tweed Airport, 4 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
New Haven 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 | 38° | 31° | 1.9 | 32° | 38° | – | – |
| Feb | 40° | 32° | 2.7 | 31° | 37° | – | – |
| Mar | 47° | 39° | 3.7 | 36° | 42° | – | – |
| Apr | 58° | 49° | 4.9 | 45° | 51° | – | – |
| May | 68° | 59° | 5.5 | 56° | 62° | – | – |
| Jun | 76° | 68° | 5.9 | 66° | 72° | $121 | $154 |
| Jul | 82° | 74° | 6.0 | 74° | 80° | $1 | $2 |
| Aug | 81° | 73° | 5.3 | 76° | 82° | – | – |
| Sep | 75° | 66° | 4.4 | 71° | 77° | $50 | $62 |
| Oct | 64° | 55° | 2.9 | 60° | 66° | – | – |
| Nov | 53° | 45° | 2.1 | 49° | 55° | – | – |
| Dec | 44° | 36° | 1.5 | 39° | 45° | – | – |
Heating costs most in Jun (about $121 with a heat pump, $154 with gas). Sunshine peaks in Jul at 6.0 kWh/m²/day (NASA satellite data, 41.2 km grid cell). Highlighted months are swimmable with no heater.
How New Haven compares with nearby cities
New Haven ranks 9 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 |
|---|---|---|---|---|
| West Haven, CT | 3 mi | 0 | 4 | $172 |
| Ansonia, CT | 8 mi | 0 | 4 | $210 |
| Derby, CT | 8 mi | 0 | 4 | $210 |
| Milford, CT | 9 mi | 0 | 4 | $119 |
| Shelton, CT | 11 mi | 0 | 4 | $210 |
| Naugatuck, CT | 14 mi | 0 | 5 | $456 |