Pool swim season in Stamford, CT
When can you swim in an outdoor pool in Stamford, CT?
An unheated pool in Stamford never reaches 78°F in a normal year. It peaks around 76°F in Aug. The air allows up to 5 swimmable months with a heater (May to Sep).
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Heater options for a Stamford pool, side by side
| 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 | $398 | $948 |
| Gas heater + cover | 5 | May to Sep | $480 | $905 |
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 Stamford
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: Stamford 5 N, 3.1 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Stamford 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° | 30° | 1.8 | 31° | 37° | – | – |
| Feb | 41° | 32° | 2.7 | 31° | 37° | – | – |
| Mar | 49° | 40° | 3.7 | 37° | 43° | – | – |
| Apr | 62° | 51° | 4.8 | 47° | 53° | – | – |
| May | 72° | 61° | 5.4 | 59° | 65° | $259 | $302 |
| Jun | 80° | 69° | 5.9 | 68° | 74° | $89 | $116 |
| Jul | 85° | 75° | 6.0 | 75° | 81° | – | – |
| Aug | 83° | 73° | 5.3 | 76° | 82° | – | – |
| Sep | 76° | 66° | 4.3 | 71° | 77° | $50 | $62 |
| Oct | 64° | 55° | 2.9 | 60° | 66° | – | – |
| Nov | 53° | 44° | 2.0 | 48° | 54° | – | – |
| Dec | 43° | 35° | 1.5 | 38° | 44° | – | – |
Heating costs most in May (about $259 with a heat pump, $302 with gas). Sunshine peaks in Jul at 6.0 kWh/m²/day (NASA satellite data, 46.9 km grid cell). Highlighted months are swimmable with no heater.
How Stamford compares with nearby cities
Stamford ranks 5 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 |
|---|---|---|---|---|
| Norwalk, CT | 7 mi | 0 | 5 | $398 |
| Port Chester, NY | 8 mi | 0 | 4 | $178 |
| Harrison, NY | 10 mi | 0 | 4 | $178 |
| White Plains, NY | 11 mi | 0 | 4 | $178 |
| Rye, NY | 12 mi | 0 | 4 | $171 |
| Mount Kisco, NY | 13 mi | 0 | 4 | $289 |