Alert archive / California / Excessive Heat Warnings
Excessive Heat Warnings in California, 2021
61 excessive heat warnings in 2021. 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 2021. Tap one for its archive.
- Excessive Heat Warnings
- 61
- Busiest month
- June22 excessive heat warnings
- Busiest day
- July 7, 20216 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 |
|---|---|---|---|---|
| May 28, 1:48 PM PDT | Excessive Heat Warning | STO | 6 days | |
| May 29, 8:26 AM PDT | Excessive Heat Warning | HNX | 3 days | |
| May 31, 3:54 AM PDT | Excessive Heat Warning | HNX | 64 hr | |
| May 31, 1:32 PM PDT | Excessive Heat Warning | VEF | Inyo, San Bernardino | 5 days |
| Jun 1, 2:08 PM PDT | Excessive Heat Warning | SGX | Riverside, San Bernardino, San Diego | 3 days |
| Jun 2, 2:15 AM PDT | Excessive Heat Warning | PSR | Imperial, Riverside, San Bernardino | 67 hr |
| Jun 2, 2:51 AM PDT | Excessive Heat Warning | HNX | 41 hr | |
| Jun 3, 12:08 PM PDT | Excessive Heat Warning | HNX | 32 hr | |
| Jun 9, 2:11 PM PDT | Excessive Heat Warning | PSR | Imperial, Riverside, San Bernardino | 11 days |
| Jun 10, 1:21 PM PDT | Excessive Heat Warning | VEF | Inyo, San Bernardino | 10 days |
| Jun 10, 1:37 PM PDT | Excessive Heat Warning | SGX | Orange, Riverside, San Bernardino, San Diego | 10 days |
| Jun 11, 1:54 PM PDT | Excessive Heat Warning | HNX | 9 days | |
| Jun 13, 6:06 PM PDT | Excessive Heat Warning | LOX | Los Angeles, Santa Barbara | 7 days |
| Jun 14, 1:17 PM PDT | Excessive Heat Warning | MTR | Alameda, Contra Costa, Monterey, San Benito | 4 days |
| Jun 14, 2:03 PM PDT | Excessive Heat Warning | STO | 6 days | |
| Jun 15, 3:13 AM PDT | Excessive Heat Warning | EKA | Lake | 5 days |
| Jun 18, 1:37 PM PDT | Excessive Heat Warning | MFR | Siskiyou | 3 days |
| Jun 23, 2:20 PM PDT | Excessive Heat Warning | MFR | Modoc, Siskiyou | 7 days |
| Jun 24, 1:51 PM PDT | Excessive Heat Warning | STO | 5 days | |
| Jun 24, 1:56 PM PDT | Excessive Heat Warning | EKA | Lake, Mendocino, Trinity | 5 days |
| Jun 25, 12:50 PM PDT | Excessive Heat Warning | VEF | Inyo, San Bernardino | 3 days |
| Jun 25, 1:05 PM PDT | Excessive Heat Warning | SGX | Riverside, San Bernardino, San Diego | 3 days |
| Jun 25, 1:10 PM PDT | Excessive Heat Warning | HNX | 4 days | |
| Jun 25, 1:34 PM PDT | Excessive Heat Warning | LOX | Los Angeles, Santa Barbara | 3 days |
| Jun 25, 1:44 PM PDT | Excessive Heat Warning | REV | Lassen, Modoc, Plumas, Sierra | 5 days |
| Jun 26, 2:20 AM PDT | Excessive Heat Warning | PSR | Imperial, Riverside, San Bernardino | 66 hr |
| Jul 6, 11:40 AM PDT | Excessive Heat Warning | HNX | 7 days | |
| Jul 6, 1:26 PM PDT | Excessive Heat Warning | SGX | Riverside, San Bernardino, San Diego | 6 days |
| Jul 6, 1:37 PM PDT | Excessive Heat Warning | VEF | Inyo, San Bernardino | 7 days |
| Jul 7, 9:15 AM PDT | Excessive Heat Warning | REV | Lassen, Modoc, Plumas, Sierra | 6 days |
| Jul 7, 12:08 PM PDT | Excessive Heat Warning | EKA | Lake, Mendocino, Trinity | 5 days |
| Jul 7, 12:40 PM PDT | Excessive Heat Warning | LOX | Santa Barbara | 5 days |
| Jul 7, 1:21 PM PDT | Excessive Heat Warning | MFR | Siskiyou | 6 days |
| Jul 7, 1:42 PM PDT | Excessive Heat Warning | PSR | Imperial, Riverside, San Bernardino | 5 days |
| Jul 7, 2:27 PM PDT | Excessive Heat Warning | STO | 5 days | |
| Jul 8, 3:33 AM PDT | Excessive Heat Warning | MTR | Alameda, Contra Costa, Monterey, San Benito, San Mateo, Santa Clara and 1 more | 4 days |
| Jul 28, 3:01 AM PDT | Excessive Heat Warning | MFR | Siskiyou | 65 hr |
| Aug 2, 11:38 AM PDT | Excessive Heat Warning | SGX | Riverside, San Bernardino, San Diego | 3 days |
| Aug 2, 11:55 AM PDT | Excessive Heat Warning | LOX | 56 hr | |
| Aug 2, 12:10 PM PDT | Excessive Heat Warning | HNX | 56 hr | |
| Aug 2, 12:48 PM PDT | Excessive Heat Warning | VEF | Inyo, San Bernardino | 3 days |
| Aug 2, 1:45 PM PDT | Excessive Heat Warning | PSR | Imperial, Riverside, San Bernardino | 3 days |
| Aug 9, 11:28 AM PDT | Excessive Heat Warning | MFR | Siskiyou | 5 days |
| Aug 13, 10:59 AM PDT | Excessive Heat Warning | LOX | Santa Barbara | 3 days |
| Aug 13, 12:50 PM PDT | Excessive Heat Warning | HNX | 3 days | |
| Aug 13, 1:47 PM PDT | Excessive Heat Warning | SGX | San Bernardino | 3 days |
| Aug 13, 2:18 PM PDT | Excessive Heat Warning | VEF | Inyo, San Bernardino | 3 days |
| Aug 24, 1:20 PM PDT | Excessive Heat Warning | PSR | Imperial, Riverside, San Bernardino | 5 days |
| Aug 24, 1:30 PM PDT | Excessive Heat Warning | SGX | Riverside, San Bernardino, San Diego | 5 days |
| Aug 25, 12:50 AM PDT | Excessive Heat Warning | VEF | San Bernardino | 6 days |
| Aug 26, 2:07 AM PDT | Excessive Heat Warning | VEF | Inyo, San Bernardino | 5 days |
| Aug 27, 12:33 PM PDT | Excessive Heat Warning | HNX | 3 days | |
| Aug 27, 1:57 PM PDT | Excessive Heat Warning | LOX | 3 days | |
| Sep 5, 1:50 AM PDT | Excessive Heat Warning | SGX | San Bernardino | 4 days |
| Sep 5, 2:02 AM PDT | Excessive Heat Warning | VEF | Inyo, San Bernardino | 5 days |
| Sep 5, 3:00 AM PDT | Excessive Heat Warning | HNX | 4 days | |
| Sep 6, 10:19 AM PDT | Excessive Heat Warning | LOX | 58 hr | |
| Sep 6, 12:12 PM PDT | Excessive Heat Warning | PSR | Imperial, Riverside, San Bernardino | 3 days |
| Sep 8, 7:50 AM PDT | Excessive Heat Warning | HNX | Kern | 13 hr |
| Sep 10, 1:48 AM PDT | Excessive Heat Warning | VEF | San Bernardino | 4 days |
| Sep 10, 2:19 AM PDT | Excessive Heat Warning | PSR | Imperial, Riverside, San Bernardino | 4 days |
By county
Every county with at least one alert. A county page lists each alert that covered it.
- San Bernardino County26
- Riverside County14
- Inyo County8
- Imperial County8
- San Diego County6
- Siskiyou County5
- Santa Barbara County4
- Lake County3
- Modoc County3
- Los Angeles County2
- Alameda County2
- Contra Costa County2
- Monterey County2
- San Benito County2
- Mendocino County2
- Trinity County2
- Lassen County2
- Plumas County2
- Sierra County2
- Orange County1
- San Mateo County1
- Santa Clara County1
- Santa Cruz County1
- Kern County1
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordThe radar archive20202022
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. Rebuilt daily.