Extreme Heat Warnings in California
60 extreme heat warnings since 1986. An alert counts here when it covered any part of the state, so the counties below add up to more than the state. The archive of extreme heat warnings reaches back to 2005.
Extreme Heat Warnings by county
Each county as a circle sized by its count since 1986. Tap one for its archive.
- Extreme Heat Warnings
- 60
- Busiest year
- 202635 extreme heat warnings
- Average year
- 30over 2 years on file
Over time
By year
Before late 2005 the archive holds only tornado, severe thunderstorm, flash flood and marine warnings, and from 1997 SPC's watches, so the jump that year is the archive widening, not the weather.
By month of the year
By county
Every county with at least one alert. A county page lists each alert that covered it.
- San Bernardino County27
- Riverside County25
- Imperial County14
- Inyo County13
- San Diego County12
- Los Angeles County8
- Santa Barbara County7
- Ventura County6
- Kern County5
- San Luis Obispo County4
- Orange County4
- Siskiyou County3
- Fresno County2
- Kings County2
- Madera County2
- Merced County2
- Tulare County2
- Mariposa County2
- Humboldt County1
- Del Norte County1
- Trinity County1
- Plumas County1
- Shasta County1
- Tehama County1
- Butte County1
The latest extreme heat warnings
The most recent on file, newest first.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 8, 10:49 AM PDT | Extreme Heat Warning | LOX | Los Angeles, San Luis Obispo, Santa Barbara, Ventura | 57 hr |
| Sep 8, 12:09 AM PDT | Extreme Heat Warning | VEF | Inyo, San Bernardino | 68 hr |
| Sep 7, 11:09 AM PDT | Extreme Heat Warning | SGX | Orange, Riverside, San Bernardino, San Diego | 4 days |
| Sep 7, 12:33 AM PDT | Extreme Heat Warning | PSR | Imperial, Riverside | 5 days |
| Aug 24, 12:44 PM PDT | Extreme Heat Warning | LOX | Los Angeles, Santa Barbara, Ventura | 4 days |
| Aug 24, 7:22 AM PDT | Extreme Heat Warning | VEF | Inyo, San Bernardino | 5 days |
| Aug 23, 4:36 PM PDT | Extreme Heat Warning | HNX | Kern | 3 days |
| Aug 19, 12:58 AM PDT | Extreme Heat Warning | SGX | Orange, Riverside, San Bernardino, San Diego | 11 days |
| Aug 17, 2:14 AM PDT | Extreme Heat Warning | VEF | Inyo, San Bernardino | 7 days |
| Aug 15, 10:05 AM PDT | Extreme Heat Warning | PSR | Imperial, Riverside, San Bernardino | 14 days |
| Aug 2, 8:23 PM PDT | Extreme Heat Warning | LOX | Santa Barbara | 7 days |
| Jul 28, 9:57 AM PDT | Extreme Heat Warning | LOX | Los Angeles, San Luis Obispo, Santa Barbara, Ventura | 12 days |
Nearby
Sources
National Weather Service watches, warnings, advisories and statements from the Iowa Environmental Mesonet's VTEC archive, which reconstructs tornado, severe thunderstorm, flash flood and marine warnings back to 1986 from the NWS text archive. Storm Prediction Center watches and mesoscale discussions from SPC's archive through the Mesonet. County centers from the US Census Bureau. Warning verification from the Mesonet's Cow. Rebuilt daily.