Severe Heatwave ● Closed

Extreme Heat Watch issued September 30 at 8:47PM PDT until October 7 at 9:00PM PDT by NWS San Diego CA, United States of America

Icon = what happened · ring colour = how serious: Extreme Severe Moderate Minor

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 around 105 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

Coordinates39.9645, -100.8105
RegionSan Diego County Coastal Areas; San Bernardino and Riverside County Valleys-The Inland Empire; San Diego County Inland Valleys; Santa Ana Mountains and Foo
Location Precisioncountry
Issuing AuthorityUnited States of America — us-noaa-nws-en
Cap UrgencyFuture
Cap CertaintyLikely
Cap Expires2026-10-01T06:15:00-07:00

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 report

This event as JSON · API and licence

Source updated 18 days ago (Oct 1, 2026 03:48 UTC) · we last heard from WMO Alert Hub (national weather services) 23 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.

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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.