Pool swim season in Lewiston, ME
Swim season in Lewiston without a heater, and with one
An unheated pool in Lewiston never reaches 78°F in a normal year. It peaks around 73°F in Aug. The air allows up to 4 swimmable months with a heater (Jun to Sep).
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Heater options for a Lewiston pool, side by side
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 0 | no month | $0 | $0 |
| Solar cover only | 1 | Aug | $0 | $50 |
| Solar panels + cover | 3 | Jul to Sep | $0 | $283 |
| Heat pump + cover | 4 | Jun to Sep | $410 | $960 |
| Gas heater + cover | 4 | Jun to Sep | $514 | $939 |
For a 450 sq ft pool held at 80°F, at ME prices of 30.2¢/kWh electricity and $19/Mcf gas. All-in spreads the purchase over the equipment's life.
The cheapest way to the full season in Lewiston
Solar panels + cover: 3 of 4 possible months for about $283 a year all-in, which works out near $94 for each month it adds.
Before you pay for any heater, buy a solar cover: on its own it adds 1 month 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: Lewiston, 2.3 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Lewiston 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 | 28° | 20° | 1.6 | 22° | 28° | – | – |
| Feb | 32° | 23° | 2.5 | 21° | 27° | – | – |
| Mar | 40° | 31° | 3.6 | 28° | 34° | – | – |
| Apr | 53° | 44° | 4.6 | 39° | 45° | – | – |
| May | 65° | 56° | 5.2 | 52° | 58° | – | – |
| Jun | 74° | 65° | 5.6 | 63° | 69° | $195 | $245 |
| Jul | 80° | 71° | 5.7 | 71° | 77° | $56 | $75 |
| Aug | 79° | 70° | 5.2 | 73° | 79° | $25 | $34 |
| Sep | 70° | 61° | 4.2 | 67° | 73° | $134 | $160 |
| Oct | 58° | 49° | 2.6 | 55° | 61° | – | – |
| Nov | 45° | 38° | 1.7 | 43° | 49° | – | – |
| Dec | 34° | 27° | 1.2 | 31° | 37° | – | – |
Heating costs most in Jun (about $195 with a heat pump, $245 with gas). Sunshine peaks in Jul at 5.7 kWh/m²/day (NASA satellite data, 52.6 km grid cell). Highlighted months are swimmable with no heater.
How Lewiston compares with nearby cities
Lewiston ranks 1 of 11 Maine cities for unheated swim months, and no nearby city gets a longer unheated season.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Auburn, ME | 4 mi | 0 | 4 | $410 |
| Augusta, ME | 28 mi | 0 | 4 | $452 |
| Westbrook, ME | 28 mi | 0 | 4 | $433 |
| Portland, ME | 32 mi | 0 | 4 | $433 |
| South Portland, ME | 32 mi | 0 | 4 | $433 |
| Waterville, ME | 40 mi | 0 | 4 | $486 |