As can occur this time of year, the coast is seeing its hottest temperatures of the year (and in some places, daily record highs) here in early October, courtesy of offshore winds.
Morning easterly winds will become progressively weaker Sunday through Tuesday, lessening the potential each day for temperatures to spike into the upper 90s at the coast in the mornings before the sea breeze knocks them down in the afternoons. As a result, forecasted highs at the coast drop from widespread upper 90s Sunday to widespread upper 80s by Wednesday.
Data Courtesy of San Diego Weather Forecast Office
Evaporative Cooler Effectiveness by City
Thousand Palms
Outside Temp103°F
Dew Point54°F
Est. Output78°F
Updated: Oct 3, 3:29 PM PDT
Palm Desert (Hwy 111 & El Paseo)
Outside Temp103°F
Dew Point55°F
Est. Output79°F
Updated: Oct 3, 3:26 PM PDT
Palm Springs Airport
Outside Temp101°F
Dew Point47°F
Est. Output75°F
Updated: Oct 3, 2:53 PM PDT
Thermal Airport
Outside Temp102°F
Dew Point51°F
Est. Output77°F
Updated: Oct 3, 2:52 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)
