Pool swim season in Surprise, AZ
When can you swim in an outdoor pool in Surprise, AZ?
An unheated pool in Surprise reaches 78°F in Jun to Oct, about 5 months a year. The air allows up to 9 swimmable months with a heater (Mar to Nov).
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What each heater buys you in Surprise
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 5 | Jun 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 | 9 | Mar to Nov | $254 | $804 |
| Gas heater + cover | 9 | Mar to Nov | $589 | $1,014 |
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 Surprise
Solar panels + cover: 8 of 9 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 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: Wittmann 1SE, 8.4 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Surprise 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 | 65° | 52° | 3.4 | 52° | 58° | – | – |
| Feb | 68° | 55° | 4.4 | 55° | 61° | – | – |
| Mar | 75° | 60° | 5.9 | 60° | 66° | $128 | $292 |
| Apr | 82° | 66° | 7.3 | 68° | 74° | $56 | $138 |
| May | 92° | 76° | 8.2 | 76° | 82° | – | – |
| Jun | 102° | 86° | 8.5 | 86° | 92° | – | – |
| Jul | 105° | 91° | 7.5 | 93° | 99° | – | – |
| Aug | 103° | 90° | 6.9 | 94° | 100° | – | – |
| Sep | 98° | 84° | 6.2 | 90° | 96° | – | – |
| Oct | 87° | 72° | 5.0 | 80° | 86° | – | – |
| Nov | 74° | 60° | 3.8 | 67° | 73° | $70 | $159 |
| Dec | 64° | 52° | 3.1 | 56° | 62° | – | – |
Heating costs most in Mar (about $128 with a heat pump, $292 with gas). Sunshine peaks in Jun at 8.5 kWh/m²/day (NASA satellite data, 19.5 km grid cell). Highlighted months are swimmable with no heater.
How Surprise compares with nearby cities
Surprise ranks 26 of 44 Arizona cities for unheated swim months; El Mirage, Glendale, Buckeye nearby get a longer season without a heater.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| El Mirage, AZ | 9 mi | 6 | 9 | $194 |
| Peoria, AZ | 12 mi | 5 | 9 | $254 |
| Glendale, AZ | 18 mi | 6 | 9 | $194 |
| Buckeye, AZ | 20 mi | 6 | 10 | $308 |
| Phoenix, AZ | 22 mi | 6 | 9 | $174 |
| Avondale, AZ | 26 mi | 6 | 10 | $296 |