National Weather ServiceCaliforniaFlash Flood WarningArchive to October 1, 2026
Flash Flood Warnings in California
The National Weather Service issued 236 flash flood warnings for California in 2025 and 177 a year on average in 2008-2025; in 2021-2025 it had the 4th most of any state. 2026 through September: 51, 67% below the average of 152 for those months in 2008-2025. San Bernardino was covered most often (1,062 times since 2008).
How many flash flood warnings does California get?
Every flash flood warning that covered part of California. 2026 is an outline: the year is not over.
The numbers
| Year | Count |
|---|---|
| 2026 (through September) | 51 |
| 2025 | 236 |
| 2024 | 129 |
| 2023 | 240 |
| 2022 | 307 |
| 2021 | 154 |
| 2020 | 68 |
| 2019 | 175 |
| 2018 | 149 |
| 2017 | 258 |
| 2016 | 124 |
| 2015 | 226 |
| 2014 | 215 |
| 2013 | 244 |
| 2012 | 183 |
| 2011 | 122 |
| 2010 | 126 |
| 2009 | 52 |
| 2008 | 171 |
Source: Iowa Environmental Mesonet archive of National Weather Service watches, warnings and advisories (VTEC); National Weather Service. Data as of October 1, 2026.
When in the year does California get them?
Sum of 2008-2025; the busiest month is labelled.
Source: Iowa Environmental Mesonet archive of National Weather Service watches, warnings and advisories (VTEC); National Weather Service. Data as of October 1, 2026.
Where in California?
| County or forecast zone | Since 2008 | Since 2023 | Last issued |
|---|---|---|---|
| San Bernardino | 1,062 | 177 | September 29, 2026 |
| Riverside | 454 | 61 | September 29, 2026 |
| Inyo | 317 | 50 | August 11, 2026 |
| San Diego | 258 | 35 | August 11, 2026 |
| Los Angeles | 246 | 77 | February 16, 2026 |
| Imperial | 158 | 42 | September 2, 2026 |
| Kern | 158 | 48 | December 24, 2025 |
| Ventura | 127 | 48 | August 11, 2026 |
| Santa Barbara | 100 | 32 | January 3, 2026 |
| Mariposa | 64 | 17 | December 26, 2025 |
| Mono | 64 | 10 | August 8, 2026 |
| Tulare | 61 | 17 | December 25, 2025 |
The NWS issues these products for counties or forecast zones; a zone can be part of a county or a mountain range.
Source: Iowa Environmental Mesonet archive of National Weather Service watches, warnings and advisories (VTEC); National Weather Service. Data as of October 1, 2026.
The latest flash flood warnings for California in AreaZine's record
NWS San DiegoWarningSeptember 28, 2026
Flash Flood Warning: Riverside, CA
Expired 12:15 a.m. PDT, September 29, 2026
NWS Las VegasWarningSeptember 28, 2026
Flash Flood Warning: San Bernardino, CA
Expired 9:15 p.m. PDT, September 28, 2026
NWS Las VegasWarningSeptember 28, 2026
Flash Flood Warning: Mohave and San Bernardino, AZ and CA
Expired 8:00 p.m. PDT, September 28, 2026
NWS Las VegasWarningSeptember 28, 2026
Flash Flood Warning: Mohave, San Bernardino and Clark, AZ and CA
Expired 7:15 p.m. PDT, September 28, 2026
NWS Las VegasWarningSeptember 28, 2026
Flash Flood Warning: San Bernardino and Clark, CA and NV
Expired 6:30 p.m. PDT, September 28, 2026
NWS San DiegoWarningSeptember 24, 2026
Flash Flood Warning: Riverside and San Bernardino, CA
Expired 7:30 p.m. PDT, September 24, 2026
NWS Las VegasWarningSeptember 24, 2026
Flash Flood Warning: San Bernardino, CA
Expired 6:15 p.m. PDT, September 24, 2026
NWS San DiegoWarningSeptember 24, 2026
Flash Flood Warning: Riverside, CA
Expired 4:30 p.m. PDT, September 24, 2026
This list is AreaZine's record of the NWS alert feed, kept since April 6, 2026; the counts above come from the complete IEM archive.
Source: National Weather Service alerts (api.weather.gov).
What is a flash flood warning?
A flash flood warning means flash flooding is happening or about to happen: water rising fast in streams, streets or dry washes, usually within six hours of heavy rain or a dam or levee failure. A warning means the hazard is happening, about to happen, or very likely: act now to protect people and property. The national record · Every warning type in California.