Areas Affected: Coachella Valley - San Diego County Deserts - San Gorgonio Pass Near Banning
This Notice Updated: Wed, 10/7 11:47am
Updated: Wed, 10/7 2:03pm
Urgency: Expected
Next Update: Thu, 10/8 6:00am
Severity: Severe
Certainty: Likely
Details:
* WHAT...Dangerously hot conditions with temperatures 105 to 108
expected. Low temperatures in the upper 70s to low 80s.
* WHERE...Coachella Valley, San Diego County Deserts, and San
Gorgonio Pass near Banning.
* WHEN...Until 8 PM PDT Friday.
* IMPACTS...Heat related illnesses increase significantly during
extreme heat events.
Information:
Drink plenty of fluids, stay in an air-conditioned room, stay out of
the sun, and check up on relatives and neighbors.
Take extra precautions when outside. Wear lightweight and loose
fitting clothing. Try to limit strenuous activities to early morning
or evening. Take action when you see symptoms of heat exhaustion and
heat stroke.
Hot conditions will continue west of the mountains through Thursday and in the deserts through Friday. Cool down is expected through the weekend.
Data Courtesy of San Diego Weather Forecast Office
Evaporative Cooler Effectiveness by City
Thousand Palms
Outside Temp105°F
Dew Point51°F
Est. Output78°F
Updated: Oct 7, 2:05 PM PDT
Palm Desert (Hwy 111 & El Paseo)
Outside Temp106°F
Dew Point53°F
Est. Output79°F
Updated: Oct 7, 2:03 PM PDT
Palm Springs Airport
Outside Temp104°F
Dew Point46°F
Est. Output76°F
Updated: Oct 7, 12:53 PM PDT
Thermal Airport
Outside Temp106°F
Dew Point47°F
Est. Output77°F
Updated: Oct 7, 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)
EXTREME HEAT WARNING 
