San Mateo, CA
San Mateo County in California has 9 FEMA disaster declarations on record covering 1982–2023, most recently Severe Winter Storms, Flooding, Landslides, and Mudslides on Mar 10, 2023 (DR-3592). Its flood risk grade is A (Low risk), ranking #257 of 3,277 U.S. counties, with 33 NFIP flood insurance claims totaling $1,995,914 in payouts. Flood risk is relatively low compared to the national average.
FEMA Disaster Declarations in San Mateo County
The 9 most recent federally declared disasters affecting San Mateo County, CA (1982–2023). Total declarations on record: 9.
| Declared | Incident Type | Title | FEMA Disaster # |
|---|---|---|---|
| Mar 10, 2023 | Flood | Severe Winter Storms, Flooding, Landslides, and Mudslides | DR-3592 |
| Jan 14, 2023 | Flood | Severe Winter Storms, Flooding, Landslides, and Mudslides | DR-4683 |
| Jan 9, 2023 | Flood | Severe Winter Storms, Flooding, and Mudslides | DR-3591 |
| Apr 1, 2017 | Flood | Severe Winter Storms, Flooding, and Mudslides | DR-4308 |
| Mar 16, 2017 | Flood | Severe Winter Storms, Flooding, and Mudslides | DR-4305 |
| Sep 13, 2005 | Hurricane | Hurricane Katrina Evacuation | DR-3248 |
| Feb 21, 1986 | Flood | Severe Storms & Flooding | DR-758 |
| Feb 9, 1983 | Coastal Storm | Coastal Storms, Floods, Slides & Tornadoes | DR-677 |
| Jan 7, 1982 | Flood | Severe Storms, Flood, Mudslides & High Tide | DR-651 |
Score Breakdown
The composite score of 19 is calculated from four weighted factors. See our methodology for details.
Other Counties in California
| County | Grade | Score | Claims | Disasters |
|---|---|---|---|---|
| Lake | A | 19 | 28 | 8 |
| Monterey | A | 19 | 28 | 10 |
| Santa Clara | A | 19 | 39 | 8 |
| El Dorado | A | 20 | 16 | 9 |
| Shasta | A | 20 | 10 | 9 |
| Tulare | A | 20 | 21 | 9 |
More Counties in California
Frequently Asked Questions
How many FEMA disaster declarations does San Mateo County, CA have?
San Mateo County, CA has 9 federal disaster declarations on FEMA record (1982–2023). The 5 most recent are: Severe Winter Storms, Flooding, Landslides, and Mudslides (declared Mar 10, 2023, DR-3592); Severe Winter Storms, Flooding, Landslides, and Mudslides (declared Jan 14, 2023, DR-4683); Severe Winter Storms, Flooding, and Mudslides (declared Jan 9, 2023, DR-3591); Severe Winter Storms, Flooding, and Mudslides (declared Apr 1, 2017, DR-4308); Severe Winter Storms, Flooding, and Mudslides (declared Mar 16, 2017, DR-4305). Counts include flood, severe storm, hurricane, and coastal storm declarations from the OpenFEMA DisasterDeclarationsSummaries dataset.
What is the flood risk grade for San Mateo County, CA?
San Mateo County is graded A (composite score 19/100, low risk). It ranks #257 of 3,277 U.S. counties for flood risk in our scoring model. The grade combines NFIP claims density (40%), disaster frequency (25%), claim severity (20%), and year-over-year trend (15%).
How many NFIP flood insurance claims have been filed in San Mateo County?
33 NFIP flood insurance claims have been filed in San Mateo County, CA, totaling $1,995,914 in payouts. The average claim is $60,482. Source: FEMA FimaNfipClaims v2 dataset.
Has San Mateo County, CA had any recent flood disasters?
Yes. The most recent FEMA declaration affecting San Mateo County was Severe Winter Storms, Flooding, Landslides, and Mudslides on Mar 10, 2023 (DR-3592). The county has 9 declared disasters in the OpenFEMA record covering 1982–2023.
The this entity record above pulls directly from FEMA OpenFEMA datasets including the National Flood Hazard Layer and NFIP claims. What follows is the per-entity context — how this entity sits in the broader U.S. flood risk, NFIP claims, and disaster declarations distribution and which underlying factors drive the headline numbers.
Every number on this page links back to FEMA OpenFEMA datasets including the National Flood Hazard Layer and NFIP claims; the methodology page describes the inputs, refresh cadence, and known limitations of the underlying data product.
For readers using this page as a decision input, the related-entity pages elsewhere on the site provide the comparison set. The most useful comparison for this entity is typically a peer within U.S. ZIPs, counties, and states with similar size, similar exposure, or similar geography — not the national-level summary alone.
Source: FEMA OpenFEMA datasets, 2026.