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Flood in Alameda County, California
179 floods and flash floods events in the NCEI Storm Events record, 1950 to 2026. Event types counted: Flood, Flash Flood, Coastal Flood, Lakeshore Flood.
NCEI notes that Storm Data is compiled from a variety of sources including the National Weather Service, other federal, state and local agencies, the media and the public; that property and crop damage figures are estimates; and that some events are recorded by NWS forecast zone rather than by county. FEMA notes that NFIP claim records are redacted and aggregated to protect the privacy of policyholders. Storm records through 30 Jun 2026.
NCEI records 179 flood events in Alameda County, California, between 1950 and 2026, spread over 23 years.
February is the busiest month, with 54 of the recorded events. The last 20 years account for 156 events against 23 in the 20 years before, a change that reflects reporting practice as much as weather.
The county holds 2.5% of the 7,136 flood events recorded in California; its 24.3 per 100 square miles compares with 4.6 statewide.
NCEI attributes 1 death in the county to floods and flash floods.
Compared with California
| Measure | Alameda County | California | US |
|---|---|---|---|
| Flood events since 1950 | 179 | 7,136 | 183,559 |
| Per 100 square miles | 24.3 | 4.6 | 5.2 |
| Per 10,000 residents | 1.1 | 1.8 | 5.5 |
| Deaths recorded | 1 | 121 | 2,961 |
| Busiest month | February | January | June |
By year
Seasonality
45Feb
54Mar
7Apr
10May
0Jun
0Jul
0Aug
0Sep
0Oct
4Nov
26Dec
33
Recorded events
All 179 events, most recent first. Magnitude is hail size, tornado rating or wind speed as recorded.
| Date | Event type | Magnitude | Property damage | Crop damage | Deaths | Injuries | Geography |
|---|---|---|---|---|---|---|---|
| 5 Jan 2026 | Flood | — | — | — | — | — | County |
| 5 Jan 2026 | Flood | — | — | — | — | — | County |
| 5 Jan 2026 | Flood | — | — | — | — | — | County |
| 4 Jan 2026 | Flood | — | — | — | — | — | County |
| 25 Dec 2025 | Flash Flood | — | — | — | — | — | County |
| 24 Dec 2025 | Flood | — | — | — | — | — | County |
| 24 Dec 2025 | Flood | — | — | — | — | — | County |
| 24 Dec 2025 | Flood | — | — | — | — | — | County |
| 24 Dec 2025 | Flood | — | — | — | — | — | County |
| 22 Dec 2025 | Flood | — | — | — | — | — | County |
| 22 Dec 2025 | Flood | — | — | — | — | — | County |
| 22 Dec 2025 | Flood | — | — | — | — | — | County |
| 22 Dec 2025 | Flood | — | — | — | — | — | County |
| 17 Nov 2025 | Flood | — | — | — | — | — | County |
| 17 Nov 2025 | Flood | — | — | — | — | — | County |
| 17 Nov 2025 | Flood | — | — | — | — | — | County |
| 13 Nov 2025 | Flood | — | — | — | — | — | County |
| 13 Feb 2025 | Flood | — | — | — | — | — | County |
| 13 Feb 2025 | Flood | — | — | — | — | — | County |
| 4 Feb 2025 | Flood | — | — | — | — | — | County |
| 29 Dec 2024 | Flood | — | — | — | — | — | County |
| 29 Dec 2024 | Flood | — | — | — | — | — | County |
| 29 Dec 2024 | Flood | — | — | — | — | — | County |
| 29 Dec 2024 | Flood | — | — | — | — | — | County |
| 29 Dec 2024 | Flood | — | — | — | — | — | County |
| 27 Dec 2024 | Flood | — | — | — | — | — | County |
| 26 Dec 2024 | Flood | — | — | — | — | — | County |
| 14 Dec 2024 | Flood | — | — | — | — | — | County |
| 23 Nov 2024 | Flood | — | $10 | — | — | — | County |
| 22 Nov 2024 | Flood | — | $10 | — | — | — | County |
| 22 Nov 2024 | Flood | — | $10 | — | — | — | County |
| 22 Nov 2024 | Flood | — | $10 | — | — | — | County |
| 22 Nov 2024 | Flood | — | $10 | — | — | — | County |
| 22 Nov 2024 | Flood | — | $10 | — | — | — | County |
| 22 Nov 2024 | Flood | — | $10 | — | — | — | County |
| 13 Apr 2024 | Flood | — | $10 | — | — | — | County |
| 2 Mar 2024 | Flood | — | — | — | — | — | County |
| 18 Feb 2024 | Flood | — | — | — | — | — | County |
| 18 Feb 2024 | Flood | — | — | — | — | — | County |
| 18 Feb 2024 | Flood | — | — | — | — | — | County |
| 18 Feb 2024 | Flood | — | — | — | — | — | County |
| 18 Feb 2024 | Flood | — | — | — | — | — | County |
| 3 Feb 2024 | Flood | — | $10 | — | — | — | County |
| 1 Feb 2024 | Flood | — | — | — | — | — | County |
| 31 Jan 2024 | Flood | — | — | — | — | — | County |
| 22 Jan 2024 | Flood | — | $10 | — | — | — | County |
| 22 Jan 2024 | Flood | — | $10 | — | — | — | County |
| 22 Jan 2024 | Flood | — | $10 | — | — | — | County |
| 21 Jan 2024 | Flood | — | $10 | — | — | — | County |
| 29 Mar 2023 | Flood | — | — | — | — | — | County |
| 10 Mar 2023 | Flood | — | — | — | 1 | 1 | County |
| 27 Feb 2023 | Flood | — | $10 | — | — | — | County |
| 27 Feb 2023 | Flood | — | $10 | — | — | — | County |
| 5 Jan 2023 | Flood | — | — | — | — | — | County |
| 31 Dec 2022 | Flood | — | — | — | — | — | County |
| 13 Dec 2021 | Flood | — | — | — | — | — | County |
| 9 Nov 2021 | Flood | — | — | — | — | — | County |
| 10 Mar 2021 | Flood | — | — | — | — | — | County |
| 28 Jan 2021 | Flood | — | — | — | — | — | County |
| 28 Jan 2021 | Flood | — | — | — | — | — | County |
| 5 Apr 2020 | Flood | — | — | — | — | — | County |
| 16 Jan 2020 | Flood | — | — | — | — | — | County |
| 16 Jan 2020 | Flood | — | — | — | — | — | County |
| 16 Jan 2020 | Flood | — | — | — | — | — | County |
| 16 Jan 2020 | Flood | — | — | — | — | — | County |
| 16 Jan 2020 | Flood | — | — | — | — | — | County |
| 16 Jan 2020 | Flood | — | — | — | — | — | County |
| 16 Jan 2020 | Flood | — | — | — | — | — | County |
| 16 Jan 2020 | Flood | — | — | — | — | — | County |
| 16 Jan 2020 | Flood | — | — | — | — | — | County |
| 16 Jan 2020 | Flood | — | — | — | — | — | County |
| 16 Jan 2020 | Flood | — | — | — | — | — | County |
| 22 Dec 2019 | Flood | — | — | — | — | — | County |
| 7 Dec 2019 | Flood | — | — | — | — | — | County |
| 7 Dec 2019 | Flood | — | — | — | — | — | County |
| 7 Dec 2019 | Flood | — | — | — | — | — | County |
| 7 Dec 2019 | Flood | — | — | — | — | — | County |
| 5 Dec 2019 | Flood | — | — | — | — | — | County |
| 30 Nov 2019 | Flood | — | — | — | — | — | County |
| 26 Nov 2019 | Flood | — | — | — | — | — | County |
| 27 Feb 2019 | Flood | — | — | — | — | — | County |
| 14 Feb 2019 | Flood | — | — | — | — | — | County |
| 14 Feb 2019 | Flood | — | — | — | — | — | County |
| 13 Feb 2019 | Flood | — | — | — | — | — | County |
| 13 Feb 2019 | Flood | — | — | — | — | — | County |
| 13 Feb 2019 | Flood | — | — | — | — | — | County |
| 13 Feb 2019 | Flood | — | — | — | — | — | County |
| 13 Feb 2019 | Flood | — | — | — | — | — | County |
| 13 Feb 2019 | Flood | — | — | — | — | — | County |
| 13 Feb 2019 | Flood | — | — | — | — | — | County |
| 4 Feb 2019 | Flood | — | — | — | — | — | County |
| 2 Feb 2019 | Flood | — | — | — | — | — | County |
| 2 Feb 2019 | Flood | — | — | — | — | — | County |
| 17 Jan 2019 | Flood | — | — | — | — | — | County |
| 17 Jan 2019 | Flood | — | — | — | — | — | County |
| 6 Jan 2019 | Flood | — | — | — | — | — | County |
| 6 Jan 2019 | Flood | — | — | — | — | — | County |
| 6 Jan 2019 | Flood | — | — | — | — | — | County |
| 6 Jan 2019 | Flood | — | — | — | — | — | County |
| 6 Jan 2019 | Flood | — | — | — | — | — | County |
| 29 Nov 2018 | Flood | — | — | — | — | — | County |
| 23 Nov 2018 | Flood | — | — | — | — | — | County |
| 23 Nov 2018 | Flood | — | — | — | — | — | County |
| 23 Nov 2018 | Flood | — | — | — | — | — | County |
| 23 Nov 2018 | Flood | — | — | — | — | — | County |
| 22 Nov 2018 | Flood | — | — | — | — | — | County |
| 22 Nov 2018 | Flood | — | — | — | — | — | County |
| 22 Nov 2018 | Flood | — | — | — | — | — | County |
| 7 Apr 2018 | Flood | — | — | — | — | — | County |
| 6 Apr 2018 | Flood | — | — | — | — | — | County |
| 6 Apr 2018 | Flood | — | — | — | — | — | County |
| 6 Apr 2018 | Flood | — | — | — | — | — | County |
| 6 Apr 2018 | Flood | — | — | — | — | — | County |
| 6 Apr 2018 | Flood | — | — | — | — | — | County |
| 22 Mar 2018 | Flood | — | — | — | — | — | County |
| 28 Feb 2018 | Flood | — | — | — | — | — | County |
| 8 Jan 2018 | Flood | — | — | — | — | — | County |
| 27 Nov 2017 | Flood | — | — | — | — | — | County |
| 7 Apr 2017 | Flood | — | — | — | — | — | County |
| 7 Apr 2017 | Flood | — | — | — | — | — | County |
| 4 Mar 2017 | Flood | — | — | — | — | — | County |
| 4 Mar 2017 | Flood | — | — | — | — | — | County |
| 21 Feb 2017 | Flood | — | — | — | — | — | County |
| 20 Feb 2017 | Flash Flood | — | — | — | — | — | County |
| 20 Feb 2017 | Flood | — | — | — | — | — | County |
| 20 Feb 2017 | Flash Flood | — | — | — | — | — | County |
| 20 Feb 2017 | Flood | — | — | — | — | — | County |
| 20 Feb 2017 | Flash Flood | — | — | — | — | — | County |
| 20 Feb 2017 | Flood | — | — | — | — | — | County |
| 20 Feb 2017 | Flood | — | — | — | — | — | County |
| 20 Feb 2017 | Flood | — | — | — | — | — | County |
| 20 Feb 2017 | Flood | — | — | — | — | — | County |
| 20 Feb 2017 | Flood | — | — | — | — | — | County |
| 20 Feb 2017 | Flood | — | — | — | — | — | County |
| 20 Feb 2017 | Flood | — | — | — | — | — | County |
| 9 Feb 2017 | Flood | — | — | — | — | — | County |
| 7 Feb 2017 | Flood | — | — | — | — | — | County |
| 7 Feb 2017 | Flood | — | — | — | — | — | County |
| 7 Feb 2017 | Flash Flood | — | — | — | — | — | County |
| 7 Feb 2017 | Flood | — | — | — | — | — | County |
| 10 Jan 2017 | Flash Flood | — | — | — | — | — | County |
| 7 Jan 2017 | Flood | — | — | — | — | — | County |
| 15 Dec 2016 | Flood | — | — | — | — | — | County |
| 6 Jan 2016 | Flood | — | — | — | — | — | County |
| 6 Feb 2015 | Flood | — | — | — | — | — | County |
| 11 Dec 2014 | Flash Flood | — | $1K | — | — | — | County |
| 11 Dec 2014 | Flood | — | — | — | — | — | County |
| 11 Dec 2014 | Flood | — | $45K | — | — | — | County |
| 2 Dec 2014 | Flood | — | — | — | — | — | County |
| 30 Nov 2014 | Flood | — | $2K | — | — | — | County |
| 30 Nov 2012 | Flood | — | $500 | — | — | — | County |
| 20 Jan 2010 | Flood | — | — | — | — | — | County |
| 13 Oct 2009 | Flood | — | — | — | — | — | County |
| 13 Oct 2009 | Flood | — | — | — | — | — | County |
| 13 Oct 2009 | Flood | — | — | — | — | — | County |
| 13 Oct 2009 | Flood | — | — | — | — | — | County |
| 1 Jan 2006 | Flood | — | $8.8M | — | — | — | County |
| 31 Dec 2005 | Flood | — | $8.8M | — | — | — | County |
| 13 Dec 2002 | Flood | — | — | — | — | — | County |
| 9 Feb 1999 | Flash Flood | — | — | — | — | — | County |
| 7 Feb 1998 | Flash Flood | — | — | — | — | — | County |
| 3 Feb 1998 | Flash Flood | — | — | — | — | — | County |
| 3 Feb 1998 | Flash Flood | — | $100K | — | — | — | County |
| 3 Feb 1998 | Flash Flood | — | $200K | — | — | — | County |
| 3 Feb 1998 | Flash Flood | — | — | — | — | — | County |
| 3 Feb 1998 | Flash Flood | — | $150K | — | — | — | County |
| 3 Feb 1998 | Flash Flood | — | $250K | — | — | — | County |
| 2 Feb 1998 | Flash Flood | — | — | — | — | — | County |
| 19 Jan 1998 | Flash Flood | — | — | — | — | — | County |
| 13 Jan 1998 | Flash Flood | — | — | — | — | — | County |
| 25 Jan 1997 | Flash Flood | — | — | — | — | — | County |
| 2 Jan 1997 | Flash Flood | — | — | — | — | — | County |
| 2 Jan 1997 | Flash Flood | — | — | — | — | — | County |
| 2 Jan 1997 | Flash Flood | — | — | — | — | — | County |
| 1 Jan 1997 | Flash Flood | — | — | — | — | — | County |
| 1 Jan 1997 | Flash Flood | — | — | — | — | — | County |
| 1 Jan 1997 | Flash Flood | — | — | — | — | — | County |
| 10 Dec 1996 | Flash Flood | — | — | — | — | — | County |
| 17 Nov 1996 | Flash Flood | — | — | — | — | — | County |
Questions and answers
How many flood events has Alameda County had?
179 events in the NCEI Storm Events record between 1950 and 2026. Reporting of floods and flash floods became far more complete after 1996, so early decades undercount.
When was the last recorded flood event in Alameda County?
5 Jan 2026 (Flood). Records reach NCEI about 120 days after the month ends.
What was the most damaging flood event recorded in Alameda County?
The flood of 31 Dec 2005, with property damage estimated by NCEI at $8.8M.
How does Alameda County compare with California for flood?
24.3 events per 100 square miles against 4.6 statewide; the county holds 179 of the state's 7,136 recorded events.
Provenance
NOAA NCEI Storm Events Database, yearly details files through 30 Jun 2026, public domain. County-recorded events plus zone-recorded events whose forecast zone is named for the county (marked "Forecast zone"). Population and area from the US Census Bureau (2021). Built 1 Oct 2026. See the methodology, the Flood hub and the county page.