Pool swim season in Mount Holly, NC

When can you swim in an outdoor pool in Mount Holly, NC?

An unheated pool in Mount Holly reaches 78°F in Jul to Aug, about 2 months a year. The air allows up to 7 swimmable months with a heater (Apr to Oct).

1. J
2. F
3. M
4. A
5. M
6. J
7. J
8. A
9. S
10. O
11. N
12. D

Heater options for a Mount Holly pool, side by side

For a 450 sq ft pool held at 80°F, at NC prices of 14.9¢/kWh electricity and $16/Mcf gas. All-in spreads the purchase over the equipment's life.

The cheapest way to the full season in Mount Holly

Solar panels + cover: 6 of 7 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 a heat pump sized to your pool's surface area; here it beats gas all-in (heat pump or gas).

Weather station: Charlotte Douglas Airport, 7 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.

Mount Holly month by month: air, sun and pool water

Heating costs most in Apr (about $133 with a heat pump, $278 with gas). Sunshine peaks in Jun at 6.3 kWh/m²/day (NASA satellite data, 49.2 km grid cell). Highlighted months are swimmable with no heater.

How Mount Holly compares with nearby cities

Mount Holly ranks 30 of 91 North Carolina cities for unheated swim months; Gastonia nearby gets a longer season without a heater.