Pool swim season in Lemon Grove, CA
Swim season in Lemon Grove without a heater, and with one
An unheated pool in Lemon Grove never reaches 78°F in a normal year. It peaks around 74°F in Aug. The air allows up to 6 swimmable months with a heater (Jun to Nov).
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Heater options for a Lemon Grove pool, side by side
| Option | Months | Swimmable | Energy/yr | All-in/yr |
|---|---|---|---|---|
| No heater | 0 | no month | $0 | $0 |
| Solar cover only | 2 | Aug to Sep | $0 | $50 |
| Solar panels + cover | 5 | Jun to Oct | $0 | $283 |
| Heat pump + cover | 6 | Jun to Nov | $456 | $1,006 |
| Gas heater + cover | 6 | Jun to Nov | $619 | $1,044 |
For a 450 sq ft pool held at 80°F, at CA prices of 32.6¢/kWh electricity and $22/Mcf gas. All-in spreads the purchase over the equipment's life.
The cheapest way to the full season in Lemon Grove
Solar panels + cover: 5 of 6 possible months for about $283 a year all-in, which works out near $57 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: Chula Vista, 7.1 mi away (NOAA 1991–2020 normals). Water temperature is estimated from air and sunshine, not measured.
Lemon Grove 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° | 57° | 3.2 | 57° | 63° | – | – |
| Feb | 67° | 58° | 4.1 | 58° | 64° | – | – |
| Mar | 67° | 59° | 5.2 | 61° | 67° | – | – |
| Apr | 68° | 61° | 6.1 | 63° | 69° | – | – |
| May | 69° | 63° | 6.1 | 65° | 71° | – | – |
| Jun | 71° | 66° | 5.9 | 68° | 74° | $118 | $163 |
| Jul | 75° | 70° | 6.1 | 71° | 77° | $52 | $76 |
| Aug | 77° | 71° | 6.1 | 74° | 80° | $7 | $11 |
| Sep | 77° | 71° | 5.4 | 73° | 79° | $12 | $18 |
| Oct | 75° | 67° | 4.3 | 70° | 76° | $74 | $103 |
| Nov | 71° | 61° | 3.4 | 64° | 70° | $193 | $248 |
| Dec | 67° | 56° | 2.9 | 59° | 65° | – | – |
Heating costs most in Nov (about $193 with a heat pump, $248 with gas). Sunshine peaks in Apr at 6.1 kWh/m²/day (NASA satellite data, 50.7 km grid cell). Highlighted months are swimmable with no heater.
How Lemon Grove compares with nearby cities
Lemon Grove ranks 283 of 376 California cities for unheated swim months; La Mesa, El Cajon nearby get a longer season without a heater.
| City | Distance | Unheated months | Heat pump months | Heat pump $/yr |
|---|---|---|---|---|
| La Mesa, CA | 3 mi | 2 | 9 | $834 |
| National City, CA | 6 mi | 0 | 6 | $456 |
| El Cajon, CA | 6 mi | 2 | 9 | $716 |
| Chula Vista, CA | 7 mi | 0 | 7 | $665 |
| San Diego, CA | 8 mi | 0 | 8 | $699 |
| Coronado, CA | 9 mi | 0 | 6 | $412 |