Pool swim season in Marana, AZ
Swim season in Marana without a heater, and with one
An unheated pool in Marana reaches 78°F in Jun to Sep, about 4 months a year. The air allows up to 9 swimmable months with a heater (Mar to Nov).
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Heater options for a Marana pool, side by side
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 4 | Jun to Sep | $0 | $0 |
| Solar cover only | 5 | Jun to Oct | $0 | $50 |
| Solar panels + cover | 7 | Apr to Oct | $0 | $283 |
| Heat pump + cover | 9 | Mar to Nov | $409 | $959 |
| Gas heater + cover | 9 | Mar to Nov | $903 | $1,328 |
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 Marana
Heat pump + cover: 9 of 9 possible months for about $959 a year all-in, which works out near $192 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 a heat pump sized to your pool's surface area; here it beats gas all-in (heat pump or gas).
Weather station: Catalina Sp, 12.4 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Marana 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 | 67° | 49° | 3.6 | 49° | 55° | – | – |
| Feb | 68° | 50° | 4.6 | 51° | 57° | – | – |
| Mar | 75° | 56° | 6.0 | 56° | 62° | $184 | $390 |
| Apr | 82° | 62° | 7.4 | 63° | 69° | $97 | $228 |
| May | 91° | 71° | 8.2 | 72° | 78° | $18 | $48 |
| Jun | 101° | 80° | 8.4 | 81° | 87° | – | – |
| Jul | 100° | 85° | 7.2 | 87° | 93° | – | – |
| Aug | 98° | 84° | 6.7 | 88° | 94° | – | – |
| Sep | 96° | 79° | 6.1 | 84° | 90° | – | – |
| Oct | 87° | 67° | 5.1 | 75° | 81° | – | – |
| Nov | 76° | 57° | 3.9 | 63° | 69° | $110 | $237 |
| Dec | 66° | 49° | 3.2 | 53° | 59° | – | – |
Heating costs most in Mar (about $184 with a heat pump, $390 with gas). Sunshine peaks in Jun at 8.4 kWh/m²/day (NASA satellite data, 34.4 km grid cell). Highlighted months are swimmable with no heater.
How Marana compares with nearby cities
Marana ranks 29 of 44 Arizona cities for unheated swim months; Tucson, Eloy, Coolidge nearby get a longer season without a heater.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| Oro Valley, AZ | 10 mi | 4 | 9 | $411 |
| Tucson, AZ | 27 mi | 5 | 9 | $206 |
| Eloy, AZ | 33 mi | 6 | 11 | $625 |
| Sahuarita, AZ | 38 mi | 4 | 9 | $262 |
| Coolidge, AZ | 39 mi | 6 | 10 | $397 |
| Florence, AZ | 45 mi | 6 | 10 | $326 |