Pool swim season in Magna, UT
When can you swim in an outdoor pool in Magna, UT?
An unheated pool in Magna reaches 78°F in Jul to Aug, about 2 months a year. The air allows up to 5 swimmable months with a heater (May to Sep).
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What each heater buys you in Magna
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 2 | Jul to Aug | $0 | $0 |
| Solar cover only | 3 | Jul to Sep | $0 | $50 |
| Solar panels + cover | 4 | Jun to Sep | $0 | $283 |
| Heat pump + cover | 5 | May to Sep | $124 | $674 |
| Gas heater + cover | 5 | May to Sep | $187 | $612 |
For a 450 sq ft pool held at 80°F, at UT prices of 13.2¢/kWh electricity and $10/Mcf gas. All-in spreads the purchase over the equipment's life.
The cheapest way to the full season in Magna
Solar panels + cover: 4 of 5 possible months for about $283 a year all-in, which works out near $142 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 gas as well as a heat pump: once the purchase price is counted, gas comes out cheaper all-in here (heat pump or gas).
Weather station: Garfield, 2.6 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Magna 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 | 36° | 31° | 2.1 | 30° | 36° | – | – |
| Feb | 42° | 35° | 3.1 | 33° | 39° | – | – |
| Mar | 53° | 45° | 4.4 | 42° | 48° | – | – |
| Apr | 60° | 52° | 5.7 | 51° | 57° | – | – |
| May | 71° | 62° | 6.8 | 61° | 67° | $108 | $160 |
| Jun | 82° | 72° | 7.8 | 72° | 78° | $16 | $27 |
| Jul | 91° | 81° | 7.4 | 81° | 87° | – | – |
| Aug | 89° | 79° | 6.6 | 84° | 90° | – | – |
| Sep | 78° | 69° | 5.4 | 76° | 82° | – | – |
| Oct | 63° | 54° | 3.9 | 62° | 68° | – | – |
| Nov | 48° | 41° | 2.5 | 47° | 53° | – | – |
| Dec | 37° | 32° | 1.8 | 35° | 41° | – | – |
Heating costs most in May (about $108 with a heat pump, $160 with gas). Sunshine peaks in Jun at 7.8 kWh/m²/day (NASA satellite data, 39.4 km grid cell). Highlighted months are swimmable with no heater.
How Magna compares with nearby cities
Magna ranks 5 of 67 Utah cities for unheated swim months, and no nearby city gets a longer unheated season.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| West Valley City, UT | 10 mi | 2 | 5 | $128 |
| Kearns, UT | 12 mi | 2 | 5 | $128 |
| Salt Lake City, UT | 13 mi | 2 | 5 | $128 |
| Taylorsville, UT | 14 mi | 2 | 5 | $128 |
| West Jordan, UT | 14 mi | 2 | 5 | $129 |
| North Salt Lake, UT | 15 mi | 1 | 5 | $194 |