Above normal temperatures continue. Highs up to 10 degrees above normal in western San Diego County and coastal Orange County.
Data Courtesy of San Diego Weather Forecast Office
Evaporative Cooler Effectiveness by City
Thousand Palms
Outside Temp93°F
Dew Point58°F
Est. Output75°F
Updated: Sep 25, 6:54 PM PDT
Palm Desert (Hwy 111 & El Paseo)
Outside Temp94°F
Dew Point63°F
Est. Output78°F
Updated: Sep 25, 6:53 PM PDT
Dew point is 63°F — humidity this high limits cooling even when the score looks OK.
Palm Springs Airport
Outside Temp97°F
Dew Point56°F
Est. Output76°F
Updated: Sep 25, 5:53 PM PDT
Thermal Airport
Outside Temp96°F
Dew Point57°F
Est. Output76°F
Updated: Sep 25, 5:52 PM PDT
How to Read This
Score
0–100, based on the wet-bulb depression — how much cooler the air could get versus the actual outside temperature. Drier air means more room to cool, so a bigger gap scores higher.
Wet-Bulb Depression
The gap between the outside (dry-bulb) temperature and the wet-bulb temperature — the coolest evaporation alone could get the air. A bigger gap means drier air and more room for the cooler to work with.
Estimated(Est.) Output
The approximate temperature of the air coming out of the cooler, estimated by cooling the outside temperature most of the way toward the wet-bulb temperature.
Efficiency
These numbers assume 80% saturation efficiency — typical for a well-maintained direct (single-stage) evaporative cooler.
Lower dew point + higher temp = better cooling
(This guide generally will work for misting systems also)
