Pool swim season in Somerton, AZ
Somerton, AZ: how long the pool season really is
An unheated pool in Somerton 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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What each heater buys you in Somerton
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 6 | May to Oct | $0 | $0 |
| Solar cover only | 8 | Apr to Nov | $0 | $50 |
| Solar panels + cover | 9 | Mar to Nov | $0 | $283 |
| Heat pump + cover | 10 | Feb to Nov | $174 | $724 |
| Gas heater + cover | 10 | Feb to Nov | $416 | $841 |
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 Somerton
Solar panels + cover: 9 of 10 possible months for about $283 a year all-in, which works out near $94 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: Yuma Mcas, 5.7 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Somerton 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 | 70° | 59° | 3.6 | 59° | 65° | – | – |
| Feb | 73° | 62° | 4.6 | 62° | 68° | $111 | $259 |
| Mar | 80° | 68° | 6.0 | 68° | 74° | $54 | $134 |
| Apr | 86° | 73° | 7.4 | 75° | 81° | – | – |
| May | 94° | 81° | 8.2 | 82° | 88° | – | – |
| Jun | 103° | 89° | 8.4 | 90° | 96° | – | – |
| Jul | 107° | 95° | 7.7 | 97° | 103° | – | – |
| Aug | 106° | 95° | 7.2 | 99° | 105° | – | – |
| Sep | 101° | 90° | 6.3 | 95° | 101° | – | – |
| Oct | 90° | 78° | 5.1 | 86° | 92° | – | – |
| Nov | 78° | 66° | 3.9 | 73° | 79° | $9 | $23 |
| Dec | 68° | 57° | 3.3 | 62° | 68° | – | – |
Heating costs most in Feb (about $111 with a heat pump, $259 with gas). Sunshine peaks in Jun at 8.4 kWh/m²/day (NASA satellite data, 21.6 km grid cell). Highlighted months are swimmable with no heater.
How Somerton compares with nearby cities
Somerton ranks 5 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 |
|---|---|---|---|---|
| San Luis, AZ | 8 mi | 6 | 10 | $174 |
| Yuma, AZ | 12 mi | 6 | 10 | $174 |
| Calexico, CA | 47 mi | 6 | 11 | $836 |
| El Centro, CA | 52 mi | 6 | 11 | $836 |
| Imperial, CA | 53 mi | 6 | 11 | $951 |
| Brawley, CA | 55 mi | 6 | 12 | $1,201 |