Map of forecast high temperatures for Southern California for Tuesday Sep 22, 2026. Temperatures will be noticeably warmer than today's, near average for this time of year.
Data Courtesy of San Diego Weather Forecast Office
Evaporative Cooler Effectiveness by City
Thousand Palms
Outside Temp98°F
Dew Point48°F
Est. Output74°F
Updated: Sep 22, 2:07 PM PDT
Palm Desert (Hwy 111 & El Paseo)
Outside Temp98°F
Dew Point49°F
Est. Output74°F
Updated: Sep 22, 2:05 PM PDT
Palm Springs Airport
Outside Temp98°F
Dew Point41°F
Est. Output72°F
Updated: Sep 22, 1:53 PM PDT
Thermal Airport
Outside Temp97°F
Dew Point44°F
Est. Output72°F
Updated: Sep 22, 1:52 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)
