Pool swim season in Norristown, PA
Norristown, PA: how long the pool season really is
An unheated pool in Norristown reaches 78°F in Jul to Aug, about 2 months a year. The air allows up to 5 swimmable months with a heater (May to Sep).
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Heater options for a Norristown pool, side by side
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 2 | Jul to Aug | $0 | $0 |
| Solar cover only | 3 | Jul to Sep | $0 | $50 |
| Solar panels + cover | 4 | Jun to Sep | $0 | $283 |
| Heat pump + cover | 5 | May to Sep | $204 | $754 |
| Gas heater + cover | 5 | May to Sep | $292 | $717 |
For a 450 sq ft pool held at 80°F, at PA prices of 21.1¢/kWh electricity and $15/Mcf gas. All-in spreads the purchase over the equipment's life.
The cheapest way to the full season in Norristown
Solar panels + cover: 4 of 5 possible months for about $283 a year all-in, which works out near $142 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: Norristown, 0.9 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Norristown 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 | 42° | 32° | 1.9 | 34° | 40° | – | – |
| Feb | 44° | 34° | 2.7 | 33° | 39° | – | – |
| Mar | 52° | 42° | 3.6 | 39° | 45° | – | – |
| Apr | 65° | 53° | 4.8 | 49° | 55° | – | – |
| May | 75° | 63° | 5.3 | 61° | 67° | $167 | $234 |
| Jun | 84° | 73° | 5.9 | 71° | 77° | $32 | $51 |
| Jul | 89° | 78° | 6.0 | 78° | 84° | – | – |
| Aug | 87° | 76° | 5.2 | 79° | 85° | – | – |
| Sep | 80° | 69° | 4.2 | 74° | 80° | $5 | $7 |
| Oct | 68° | 57° | 2.9 | 63° | 69° | – | – |
| Nov | 57° | 46° | 2.1 | 50° | 56° | – | – |
| Dec | 46° | 37° | 1.6 | 40° | 46° | – | – |
Heating costs most in May (about $167 with a heat pump, $234 with gas). Sunshine peaks in Jul at 6.0 kWh/m²/day (NASA satellite data, 44.2 km grid cell). Highlighted months are swimmable with no heater.
How Norristown compares with nearby cities
Norristown ranks 6 of 68 Pennsylvania cities for unheated swim months, and no nearby city gets a longer unheated season.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Lansdale, PA | 9 mi | 0 | 5 | $262 |
| Phoenixville, PA | 10 mi | 1 | 5 | $227 |
| Lansdowne, PA | 13 mi | 2 | 5 | $169 |
| Philadelphia, PA | 13 mi | 2 | 5 | $133 |
| Yeadon, PA | 14 mi | 2 | 5 | $169 |
| Darby, PA | 15 mi | 2 | 5 | $169 |