Pool swim season in Mesa, AZ
When can you swim in an outdoor pool in Mesa, AZ?
An unheated pool in Mesa reaches 78°F in May to Oct, about 6 months a year. The air allows up to 10 swimmable months with a heater (Feb to Nov).
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Heater options for a Mesa pool, side by side
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 6 | May to Oct | $0 | $0 |
| Solar cover only | 6 | May to Oct | $0 | $50 |
| Solar panels + cover | 8 | Apr to Nov | $0 | $283 |
| Heat pump + cover | 10 | Feb to Nov | $361 | $911 |
| Gas heater + cover | 10 | Feb to Nov | $819 | $1,244 |
For a 450 sq ft pool held at 80°F, at AZ prices of 15.4¢/kWh electricity and $19/Mcf gas. All-in spreads the purchase over the equipment's life.
The cheapest way to the full season in Mesa
Heat pump + cover: 10 of 10 possible months for about $911 a year all-in, which works out near $228 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: E Mesa, 4.3 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Mesa 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 | 68° | 54° | 3.4 | 54° | 60° | – | – |
| Feb | 70° | 56° | 4.3 | 57° | 63° | $174 | $374 |
| Mar | 77° | 62° | 5.8 | 62° | 68° | $108 | $253 |
| Apr | 85° | 69° | 7.3 | 70° | 76° | $33 | $84 |
| May | 94° | 78° | 8.2 | 79° | 85° | – | – |
| Jun | 104° | 87° | 8.5 | 88° | 94° | – | – |
| Jul | 106° | 92° | 7.4 | 94° | 100° | – | – |
| Aug | 105° | 92° | 6.9 | 96° | 102° | – | – |
| Sep | 100° | 86° | 6.1 | 92° | 98° | – | – |
| Oct | 90° | 74° | 5.0 | 82° | 88° | – | – |
| Nov | 77° | 62° | 3.8 | 69° | 75° | $46 | $108 |
| Dec | 66° | 53° | 3.0 | 58° | 64° | – | – |
Heating costs most in Feb (about $174 with a heat pump, $374 with gas). Sunshine peaks in Jun at 8.5 kWh/m²/day (NASA satellite data, 23.0 km grid cell). Highlighted months are swimmable with no heater.
How Mesa compares with nearby cities
Mesa ranks 12 of 44 Arizona cities for unheated swim months, and no nearby city gets a longer unheated season.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Gilbert, AZ | 6 mi | 6 | 9 | $206 |
| Apache Junction, AZ | 10 mi | 5 | 10 | $352 |
| Chandler, AZ | 11 mi | 6 | 11 | $550 |
| Tempe, AZ | 12 mi | 6 | 11 | $550 |
| Queen Creek, AZ | 13 mi | 6 | 9 | $206 |
| Fountain Hills, AZ | 14 mi | 6 | 9 | $184 |