Alert archive / California / Excessive Heat Warnings
Excessive Heat Warnings in California, 2020
51 excessive heat warnings in 2020. 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 excessive heat warnings reaches back to 2005.
Excessive Heat Warnings by county
Each county as a circle sized by its count in 2020. Tap one for its archive.
- Excessive Heat Warnings
- 51
- Busiest month
- August15 excessive heat warnings
- Busiest day
- May 24, 20206 excessive heat warnings
Over time
By month
The alerts
Every alert, in the order issued. Times are local, Pacific Time. Each opens its own page with the text, the map, the radar and the sounding.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 24, 1:32 PM PDT | Excessive Heat Warning | PSR | Imperial, Riverside | 71 hr |
| Apr 24, 1:41 PM PDT | Excessive Heat Warning | SGX | Riverside, San Bernardino, San Diego | 6 days |
| Apr 25, 2:11 PM PDT | Excessive Heat Warning | VEF | Inyo, San Bernardino | 5 days |
| Apr 27, 3:44 AM PDT | Excessive Heat Warning | PSR | Imperial, Riverside | 4 days |
| May 4, 1:20 PM PDT | Excessive Heat Warning | SGX | Riverside, San Diego | 4 days |
| May 5, 2:36 AM PDT | Excessive Heat Warning | PSR | Imperial, Riverside | 65 hr |
| May 7, 2:10 AM PDT | Excessive Heat Warning | VEF | Inyo | 66 hr |
| May 24, 2:32 AM PDT | Excessive Heat Warning | VEF | Inyo, San Bernardino | 6 days |
| May 24, 2:54 AM PDT | Excessive Heat Warning | SGX | Riverside, San Bernardino, San Diego | 6 days |
| May 24, 2:55 AM PDT | Excessive Heat Warning | PSR | Imperial, Riverside, San Bernardino | 8 days |
| May 24, 4:39 AM PDT | Excessive Heat Warning | LOX | 5 days | |
| May 24, 10:54 AM PDT | Excessive Heat Warning | STO | 4 days | |
| May 24, 12:33 PM PDT | Excessive Heat Warning | HNX | 4 days | |
| Jun 2, 1:06 AM PDT | Excessive Heat Warning | VEF | Inyo, San Bernardino | 67 hr |
| Jun 2, 2:04 AM PDT | Excessive Heat Warning | PSR | Imperial, Riverside, San Bernardino | 66 hr |
| Jun 2, 12:50 PM PDT | Excessive Heat Warning | SGX | Riverside, San Diego | 54 hr |
| Jul 8, 1:42 PM PDT | Excessive Heat Warning | SGX | Riverside, San Bernardino, San Diego | 5 days |
| Jul 8, 1:52 PM PDT | Excessive Heat Warning | VEF | Inyo, San Bernardino | 5 days |
| Jul 8, 2:19 PM PDT | Excessive Heat Warning | PSR | Imperial, Riverside, San Bernardino | 5 days |
| Jul 11, 2:53 AM PDT | Excessive Heat Warning | HNX | 49 hr | |
| Jul 11, 9:55 AM PDT | Excessive Heat Warning | LOX | 34 hr | |
| Jul 28, 2:57 AM PDT | Excessive Heat Warning | PSR | Imperial, Riverside, San Bernardino | 8 days |
| Jul 28, 3:42 AM PDT | Excessive Heat Warning | VEF | Inyo, San Bernardino | 5 days |
| Jul 28, 12:36 PM PDT | Excessive Heat Warning | SGX | Riverside, San Bernardino, San Diego | 5 days |
| Aug 2, 1:52 AM PDT | Excessive Heat Warning | PSR | Imperial | 66 hr |
| Aug 11, 1:27 PM PDT | Excessive Heat Warning | PSR | Imperial, Riverside, San Bernardino | 9 days |
| Aug 12, 1:10 PM PDT | Excessive Heat Warning | VEF | Inyo, San Bernardino | 9 days |
| Aug 12, 1:39 PM PDT | Excessive Heat Warning | SGX | Orange, Riverside, San Bernardino, San Diego | 9 days |
| Aug 12, 2:07 PM PDT | Excessive Heat Warning | LOX | Los Angeles, Santa Barbara | 9 days |
| Aug 13, 2:57 AM PDT | Excessive Heat Warning | HNX | 9 days | |
| Aug 13, 11:23 AM PDT | Excessive Heat Warning | EKA | Lake, Mendocino | 56 hr |
| Aug 13, 11:32 AM PDT | Excessive Heat Warning | STO | 6 days | |
| Aug 13, 1:03 PM PDT | Excessive Heat Warning | MTR | Alameda, Contra Costa, Marin, Monterey, Napa, San Benito and 4 more | 6 days |
| Aug 13, 1:13 PM PDT | Excessive Heat Warning | MFR | Siskiyou | 4 days |
| Aug 18, 2:13 AM PDT | Excessive Heat Warning | EKA | Lake, Mendocino | 18 hr |
| Aug 23, 2:25 AM PDT | Excessive Heat Warning | PSR | Imperial, Riverside, San Bernardino | 6 days |
| Aug 23, 2:42 AM PDT | Excessive Heat Warning | VEF | San Bernardino | 5 days |
| Aug 25, 3:43 AM PDT | Excessive Heat Warning | SGX | Riverside, San Diego | 4 days |
| Aug 28, 1:48 AM PDT | Excessive Heat Warning | PSR | Imperial, Riverside | 18 hr |
| Sep 2, 11:53 AM PDT | Excessive Heat Warning | VEF | Inyo, San Bernardino | 5 days |
| Sep 2, 12:12 PM PDT | Excessive Heat Warning | SGX | Orange, Riverside, San Bernardino, San Diego | 5 days |
| Sep 2, 12:24 PM PDT | Excessive Heat Warning | LOX | Los Angeles, Santa Barbara | 5 days |
| Sep 2, 1:33 PM PDT | Excessive Heat Warning | PSR | Imperial, Riverside, San Bernardino | 5 days |
| Sep 3, 1:35 AM PDT | Excessive Heat Warning | HNX | 5 days | |
| Sep 3, 10:02 AM PDT | Excessive Heat Warning | STO | 4 days | |
| Sep 3, 1:13 PM PDT | Excessive Heat Warning | MTR | Alameda, Contra Costa, Marin, Monterey, Napa, San Benito and 4 more | 4 days |
| Sep 3, 2:01 PM PDT | Excessive Heat Warning | EKA | Del Norte, Humboldt, Lake, Mendocino, Trinity | 5 days |
| Sep 5, 7:50 PM PDT | Excessive Heat Warning | MFR | Siskiyou | 48 hr |
| Sep 15, 1:57 PM PDT | Excessive Heat Warning | PSR | Imperial | 54 hr |
| Sep 30, 1:22 PM PDT | Excessive Heat Warning | LOX | Los Angeles | 31 hr |
| Sep 30, 1:30 PM PDT | Excessive Heat Warning | SGX | Orange, Riverside, San Bernardino, San Diego | 55 hr |
By county
Every county with at least one alert. A county page lists each alert that covered it.
- San Bernardino County22
- Riverside County21
- Imperial County13
- San Diego County10
- Inyo County8
- Orange County3
- Los Angeles County3
- Lake County3
- Mendocino County3
- Santa Barbara County2
- Alameda County2
- Contra Costa County2
- Marin County2
- Monterey County2
- Napa County2
- San Benito County2
- San Mateo County2
- Santa Clara County2
- Santa Cruz County2
- Sonoma County2
- Siskiyou County2
- Del Norte County1
- Humboldt County1
- Trinity County1
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordThe radar archive20192021
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.