Unscreened Exposed Pool Evaporation table
| Mo. | Unscreened Exposed | *South Facing | Floor jet system | Solar heating | **Heat Pump per 10F | ***Wind per 1mph |
|---|---|---|---|---|---|---|
| Jan | 1/8” | +1/32” | +1/32” | +1/32” | +1/16” -1/8” | +25% |
| Feb | 1/8” | +1/32” | +1/32” | +1/32” | +1/16” -1/8” | +25% |
| Mar | 3/16” | +1/32 -1/16" | +1/32 -1/16" | +1/32 -1/16" | +1/16” -1/8” | +25% |
| Apr | 3/16” | +1/32” -1/16” | +1/32” -1/16” | +1/32” -1/16” | +1/16” -1/8” | +25% |
| May | 1/4” | +1/32” -1/16” | +1/32” -1/16” | +1/16” | +1/16” -1/8” | +25% |
| Jun | 1/4” | +1/32” -1/16” | +1/32” -1/16” | +1/16” | +1/16” | +25% |
| Jul | 3/16”-1/4” | +1/32” | +1/32” | +1/32” -1/16” | +1/16” | +25% |
| Aug | 3/16”-1/4” | +1/32” | +1/32” | +1/32” -1/16” | +1/16” | +25% |
| Sep | 3/16”-1/4” | +1/32” | +1/32” | +1/32” -1/16” | +1/16” | +25% |
| Oct | 1/4” | +1/32” -1/16” | +1/32” -1/16” | +1/16” | +1/16” -1/8” | +25% |
| Nov | 3/16”-1/4” | +1/32” -1/16” | +1/32” -1/16” | +1/16” | +1/16” -1/8” | +25% |
| Dec | 1/8”-3/16” | +1/32” -1/16” | +1/32” | +1/32” -1/16” | +1/16” -1/8” | +25% |
* South-facing pools stay warmer (and evaporate more during cooler months) because they tend to absorb more sun energy and avoid northerly (winter) winds.
** Heat pump calculations are based on an every 10 degree (Fahrenheit) increment above ambient (the natural surrounding water) temperature.
*** Wind enhanced evaporation rates are based upon an every 1mph (avg.) increase in wind speed. For example, a constant 4mph wind (e.g. a cold front) would double a pool's evaporation rate.




