Pool swim season in Waterville, ME
When can you swim in an outdoor pool in Waterville, ME?
An unheated pool in Waterville never reaches 78°F in a normal year. It peaks around 71°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 Waterville
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 0 | no month | $0 | $0 |
| Solar cover only | 0 | no month | $0 | $50 |
| Solar panels + cover | 3 | Jul to Sep | $0 | $283 |
| Heat pump + cover | 4 | Jun to Sep | $486 | $1,036 |
| Gas heater + cover | 4 | Jun to Sep | $605 | $1,030 |
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 Waterville
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.
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 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: Waterville Trtmt Plt, 1.3 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Waterville 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 | 29° | 19° | 1.7 | 21° | 27° | – | – |
| Feb | 32° | 21° | 2.5 | 19° | 25° | – | – |
| Mar | 40° | 30° | 3.7 | 26° | 32° | – | – |
| Apr | 54° | 43° | 4.6 | 38° | 44° | – | – |
| May | 66° | 55° | 5.3 | 51° | 57° | – | – |
| Jun | 75° | 64° | 5.6 | 62° | 68° | $216 | $268 |
| Jul | 80° | 70° | 5.8 | 70° | 76° | $72 | $97 |
| Aug | 80° | 69° | 5.2 | 71° | 77° | $45 | $59 |
| Sep | 72° | 61° | 4.2 | 66° | 72° | $153 | $181 |
| Oct | 59° | 49° | 2.7 | 54° | 60° | – | – |
| Nov | 46° | 37° | 1.7 | 42° | 48° | – | – |
| Dec | 35° | 26° | 1.3 | 30° | 36° | – | – |
Heating costs most in Jun (about $216 with a heat pump, $268 with gas). Sunshine peaks in Jul at 5.8 kWh/m²/day (NASA satellite data, 13.8 km grid cell). Highlighted months are swimmable with no heater.
How Waterville compares with nearby cities
Waterville ranks 8 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 |
|---|---|---|---|---|
| Augusta, ME | 15 mi | 0 | 4 | $452 |
| Lewiston, ME | 40 mi | 0 | 4 | $410 |
| Auburn, ME | 43 mi | 0 | 4 | $410 |
| Bangor, ME | 47 mi | 0 | 4 | $510 |
| Westbrook, ME | 67 mi | 0 | 4 | $433 |
| Portland, ME | 68 mi | 0 | 4 | $433 |