Pool swim season in Lebanon, NH
When can you swim in an outdoor pool in Lebanon, NH?
An unheated pool in Lebanon never reaches 78°F in a normal year. It peaks around 72°F in Aug. The air allows up to 4 swimmable months with a heater (Jun to Sep).
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
What each heater buys you in Lebanon
| 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 | 4 | Jun to Sep | $0 | $283 |
| Heat pump + cover | 4 | Jun to Sep | $383 | $933 |
| Gas heater + cover | 4 | Jun to Sep | $528 | $953 |
For a 450 sq ft pool held at 80°F, at NH prices of 26.9¢/kWh electricity and $19/Mcf gas. All-in spreads the purchase over the equipment's life.
The cheapest way to the full season in Lebanon
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.
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 a heat pump sized to your pool's surface area; here it beats gas all-in (heat pump or gas).
Weather station: Lebanon Municipal Airport, 2.6 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Lebanon 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 | 30° | 20° | 1.6 | 22° | 28° | – | – |
| Feb | 34° | 22° | 2.5 | 21° | 27° | – | – |
| Mar | 43° | 32° | 3.7 | 28° | 34° | – | – |
| Apr | 57° | 44° | 4.6 | 40° | 46° | – | – |
| May | 70° | 57° | 5.2 | 53° | 59° | – | – |
| Jun | 78° | 65° | 5.6 | 64° | 70° | $163 | $226 |
| Jul | 83° | 70° | 5.8 | 71° | 77° | $50 | $75 |
| Aug | 81° | 69° | 5.2 | 72° | 78° | $35 | $51 |
| Sep | 73° | 61° | 4.2 | 66° | 72° | $135 | $176 |
| Oct | 60° | 49° | 2.6 | 54° | 60° | – | – |
| Nov | 47° | 37° | 1.7 | 42° | 48° | – | – |
| Dec | 36° | 27° | 1.2 | 30° | 36° | – | – |
Heating costs most in Jun (about $163 with a heat pump, $226 with gas). Sunshine peaks in Jul at 5.8 kWh/m²/day (NASA satellite data, 24.9 km grid cell). Highlighted months are swimmable with no heater.
How Lebanon compares with nearby cities
Lebanon ranks 8 of 11 New Hampshire cities for unheated swim months, and no nearby city gets a longer unheated season.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Claremont, NH | 18 mi | 0 | 4 | $525 |
| Rutland, VT | 36 mi | 0 | 4 | $457 |
| Laconia, NH | 39 mi | 0 | 4 | $323 |
| Concord, NH | 45 mi | 0 | 4 | $334 |
| Keene, NH | 47 mi | 0 | 4 | $458 |
| Manchester, NH | 61 mi | 0 | 4 | $327 |