Alert archive / California / Severe Thunderstorm Warnings / 2026
Severe Thunderstorm Warnings in California, September 2026
11 severe thunderstorm warnings in September 2026. 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 in September 2026. Tap one for its archive.
- Severe Thunderstorm Warnings
- 11
- Busiest day
- September 17, 20263 severe thunderstorm warnings
Over time
By day
Days in UTC, the clock the archive keeps.
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 |
|---|---|---|---|---|
| Sep 1, 5:37 PM PDT | Severe Thunderstorm Warning | PSR | Imperial | 38 min |
| Sep 8, 5:08 PM PDT | Severe Thunderstorm Warning | SGX | Riverside, San Diego | 35 min |
| Sep 16, 5:12 PM PDT | Severe Thunderstorm Warning | MFR | Siskiyou | 13 min |
| Sep 16, 5:30 PM PDT | Severe Thunderstorm Warning | EKA | Mendocino, Trinity | 45 min |
| Sep 16, 5:40 PM PDT | Severe Thunderstorm Warning | VEF | San Bernardino | 50 min |
| Sep 21, 3:29 PM PDT | Severe Thunderstorm Warning | STO | Plumas, Sierra | 30 min |
| Sep 21, 4:32 PM PDT | Severe Thunderstorm Warning | STO | Plumas | 28 min |
| Sep 21, 4:52 PM PDT | Severe Thunderstorm Warning | STO | Plumas | 23 min |
| Sep 28, 1:29 PM PDT | Severe Thunderstorm Warning | VEF | San Bernardino | 46 min |
| Sep 28, 3:47 PM PDT | Severe Thunderstorm Warning | VEF | San Bernardino | 43 min |
| Sep 28, 5:17 PM PDT | Severe Thunderstorm Warning | VEF | San Bernardino | 58 min |
By county
Every county with at least one alert. A county page lists each alert that covered it.
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.