Severe Heatwave ● Closed
Extreme Heat Watch issued September 30 at 1:41PM PDT until October 7 at 9:00PM PDT by NWS San Diego CA, United States of America
Loading live data… · Marker positions are approximate; severity is labelled in each popup. Sources: USGS, GDACS, NASA EONET, NOAA/NWS, EMSC.
* WHAT...Dangerously hot conditions with high temperatures on the
hottest days ranging from around 90 near the coast to the upper 90s
to upper 100s for the valleys possible. Low temperatures for
coastal areas into the western valleys will warm into the lower to
mid 70s during the weekend with those warm overnight temperatures
continuing for next week.
* WHERE...Orange County Coastal Areas, Orange County Inland Areas,
San Bernardino and Riverside County Valleys-The Inland Empire, San
Diego County Coastal Areas, San Diego County Valleys, and Santa Ana
Mountains and Foothills.
* WHEN...From Friday morning through Wednesday evening.
* IMPACTS...Heat related illnesses increase significantly during
extreme heat events.
* ADDITIONAL DETAILS...A long-duration heat wave is expected to
develop late this week and continue through much of next week into
the following weekend with Moderate or greater HeatRisk for the
coast and valleys and Major to Extreme HeatRisk for inland coastal
areas into the western valleys.
Measurements
| Coordinates | 39.9645, -100.8105 |
|---|---|
| Region | San Diego County Coastal Areas; San Bernardino and Riverside County Valleys-The Inland Empire; San Diego County Inland Valleys; Santa Ana Mountains and Foo |
| Location Precision | country |
| Issuing Authority | United States of America — us-noaa-nws-en |
| Cap Urgency | Future |
| Cap Certainty | Likely |
| Cap Expires | 2026-09-30T23:15:00-07:00 |
Official source
Warnings courtesy of the issuing national meteorological service, via the WMO Alert Hub.
This is an official warning issued by the authority named above. Follow its instructions and those of your local emergency services.
Severity as published by WMO Alert Hub (national weather services).
View original reportThis event as JSON · API and licence
Source updated 19 days ago (Sep 30, 2026 20:42 UTC) · we last heard from WMO Alert Hub (national weather services) 27 seconds ago
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About this location
The agency did not publish coordinates for this warning. The pin is the centre of the country, not the location of the event — read the area name, not the map, for where it applies.
Area as the agency stated it: San Diego County Coastal Areas; San Bernardino and Riverside County Valleys-The Inland Empire; San Diego County Inland Valleys; Santa Ana Mountains and Foo
Official authorities in United States
If you are there, these are the bodies whose instructions apply. This site is not an emergency service and does not issue warnings.
More for United States →What to do
Follow the instructions issued by WMO Alert Hub (national weather services) and your local emergency services. The guidance below is background.
Recognising heat exhaustion and heat stroke, keeping cool, and protecting vulnerable people during extreme heat.
Open Heatwave Safety Guide →Nearby & related events
Disclaimer: figures are automatic feeds from the named agencies and may be revised. Do not use this page for life-safety decisions — follow official local emergency services.