Heat Advisories in California
621 heat advisories 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 heat advisories reaches back to 2005.
Heat Advisories by county
Each county as a circle sized by its count since 1986. Tap one for its archive.
- Heat Advisories
- 621
- Busiest year
- 202467 heat advisories
- Average year
- 31over 20 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.
- Los Angeles County99
- Santa Clara County98
- Alameda County96
- Contra Costa County96
- Riverside County95
- Monterey County93
- San Diego County92
- San Bernardino County91
- San Benito County87
- Sonoma County86
- Napa County83
- Marin County81
- San Mateo County77
- Santa Barbara County76
- Santa Cruz County71
- Orange County71
- Mendocino County58
- Siskiyou County49
- San Luis Obispo County49
- Ventura County48
- City and County of San Francisco47
- Modoc County39
- Humboldt County38
- Trinity County35
- Lake County34
- Fresno County29
- Tulare County29
- Kern County29
- Madera County28
- Mariposa County28
- Kings County26
- Merced County25
- Del Norte County24
- Plumas County17
- Lassen County14
- Sierra County14
- Nevada County7
- Placer County7
- El Dorado County6
- Tuolumne County5
The latest heat advisories
The most recent on file, newest first.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 11, 2:30 AM PDT | Heat Advisory | SGX | Orange, Riverside, San Bernardino, San Diego | 18 hr |
| Sep 10, 9:20 PM PDT | Heat Advisory | LOX | Los Angeles, Santa Barbara, Ventura | 21 hr |
| Sep 8, 3:10 AM PDT | Heat Advisory | SGX | Orange, Riverside, San Diego | 35 hr |
| Sep 7, 11:55 AM PDT | Heat Advisory | LOX | Los Angeles, San Luis Obispo, Santa Barbara, Ventura | 44 hr |
| Sep 7, 11:09 AM PDT | Heat Advisory | SGX | Orange, Riverside, San Bernardino, San Diego | 3 days |
| Sep 7, 10:57 AM PDT | Heat Advisory | HNX | Fresno, Kern, Kings, Madera, Mariposa, Merced and 1 more | 3 days |
| Sep 7, 10:30 AM PDT | Heat Advisory | STO | Amador, Butte, Calaveras, Colusa, El Dorado, Glenn and 12 more | 3 days |
| Sep 7, 10:27 AM PDT | Heat Advisory | MTR | Alameda, Contra Costa, Marin, Monterey, Napa, San Benito and 5 more | 3 days |
| Aug 24, 12:44 PM PDT | Heat Advisory | LOX | San Luis Obispo, Santa Barbara | 4 days |
| Aug 23, 4:36 PM PDT | Heat Advisory | HNX | Fresno, Kern, Kings, Tulare | 3 days |
| Aug 22, 2:25 PM PDT | Heat Advisory | LOX | Los Angeles, San Luis Obispo, Santa Barbara, Ventura | 7 days |
| Aug 21, 12:23 PM PDT | Heat Advisory | SGX | Orange, Riverside, San Bernardino, San Diego | 8 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.