Severe Thunderstorm Warnings in California
3,575 severe thunderstorm 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 severe thunderstorm warnings reaches back to 1986.
Severe Thunderstorm Warnings by county
Each county as a circle sized by its count since 1986. Tap one for its archive.
- Severe Thunderstorm Warnings
- 3,575
- Busiest year
- 2025217 severe thunderstorm warnings
- Average year
- 87over 41 years on file
Over time
By year
Before October 2007 these were issued for whole counties, and a storm crossing three counties was often three warnings; since then one polygon follows the storm. The count changed with the practice, not only with 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 County665
- Riverside County385
- San Diego County273
- Imperial County245
- Siskiyou County211
- Fresno County166
- Plumas County161
- Kern County155
- Lassen County151
- Los Angeles County139
- Tehama County119
- Tulare County115
- Sierra County112
- Trinity County104
- Madera County98
- Placer County87
- Kings County84
- Butte County82
- El Dorado County82
- Shasta County80
- Nevada County77
- Tuolumne County76
- Alpine County68
- Santa Barbara County66
- Glenn County62
- Inyo County62
- Sacramento County57
- Mariposa County57
- Merced County54
- San Luis Obispo County49
- Ventura County48
- Orange County47
- Calaveras County45
- San Joaquin County42
- Modoc County42
- Humboldt County39
- Mono County38
- Yuba County36
- Stanislaus County36
- Sutter County30
18 more counties
- Colusa County29
- Amador County27
- Santa Cruz County27
- Santa Clara County26
- Monterey County25
- Yolo County24
- San Mateo County24
- Solano County21
- Napa County15
- Mendocino County15
- Lake County14
- City and County of San Francisco12
- San Benito County11
- Marin County11
- Contra Costa County10
- Alameda County9
- Sonoma County7
- Del Norte County6
The latest severe thunderstorm warnings
The most recent on file, newest first.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 21, 4:52 PM PDT | Severe Thunderstorm Warning | STO | Plumas | 23 min |
| Sep 21, 4:32 PM PDT | Severe Thunderstorm Warning | STO | Plumas | 28 min |
| Sep 21, 3:29 PM PDT | Severe Thunderstorm Warning | STO | Plumas, Sierra | 30 min |
| Sep 16, 5:40 PM PDT | Severe Thunderstorm Warning | VEF | San Bernardino | 50 min |
| Sep 16, 5:30 PM PDT | Severe Thunderstorm Warning | EKA | Mendocino, Trinity | 45 min |
| Sep 16, 5:12 PM PDT | Severe Thunderstorm Warning | MFR | Siskiyou | 13 min |
| Sep 8, 5:08 PM PDT | Severe Thunderstorm Warning | SGX | Riverside, San Diego | 35 min |
| Sep 1, 5:37 PM PDT | Severe Thunderstorm Warning | PSR | Imperial | 38 min |
| Aug 15, 5:42 PM PDT | Severe Thunderstorm Warning | PSR | Imperial | 24 min |
| Aug 15, 5:20 PM PDT | Severe Thunderstorm Warning | PSR | Imperial | 13 min |
| Aug 15, 4:49 PM PDT | Severe Thunderstorm Warning | VEF | San Bernardino | 41 min |
| Aug 15, 12:45 PM PDT | Severe Thunderstorm Warning | VEF | San Bernardino | 45 min |
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. Rebuilt daily.