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B

Sonoma, CA

Flood Risk Score: 21/100 · Rank #152 of 3,277 counties

Sonoma County in California has 11 FEMA disaster declarations on record covering 1964–2023, most recently Severe Winter Storms, Flooding, Landslides, and Mudslides on Mar 10, 2023 (DR-3592). Its flood risk grade is B (Moderate risk), ranking #152 of 3,277 U.S. counties, with 147 NFIP flood insurance claims totaling $3,994,861 in payouts. Flood risk is relatively low compared to the national average.

21
Risk Score
147
NFIP Claims
$3,994,861
Total Payouts
11
Disasters
$27,176
Avg Claim
147
Active Policies

FEMA Disaster Declarations in Sonoma County

The 11 most recent federally declared disasters affecting Sonoma County, CA (1964–2023). Total declarations on record: 11.

DeclaredIncident TypeTitleFEMA Disaster #
Mar 10, 2023FloodSevere Winter Storms, Flooding, Landslides, and MudslidesDR-3592
Jan 14, 2023FloodSevere Winter Storms, Flooding, Landslides, and MudslidesDR-4683
Jan 9, 2023FloodSevere Winter Storms, Flooding, and MudslidesDR-3591
Apr 1, 2017FloodSevere Winter Storms, Flooding, and MudslidesDR-4308
Sep 13, 2005HurricaneHurricane Katrina EvacuationDR-3248
Feb 3, 1993FloodSevere Winter Storm, MUD & Land Slides, & FloodingDR-979
Feb 21, 1986FloodSevere Storms & FloodingDR-758
Feb 9, 1983Coastal StormCoastal Storms, Floods, Slides & TornadoesDR-677
Jan 7, 1982FloodSevere Storms, Flood, Mudslides & High TideDR-651
Jan 26, 1969FloodSevere Storms & FloodingDR-253
Dec 24, 1964FloodHeavy Rains & FloodingDR-183

Score Breakdown

The composite score of 21 is calculated from four weighted factors. See our methodology for details.

Claims Density
40%
1
Disaster Frequency
25%
23
Claim Severity
20%
0
Year-over-Year Trend
15%
100

Other Counties in California

CountyGradeScoreClaimsDisasters
Contra CostaB213011
Santa CruzB216910
San JoaquinB221713
El DoradoA20169
ShastaA20109
TulareA20219
View All Counties in California

Frequently Asked Questions

How many FEMA disaster declarations does Sonoma County, CA have?

Sonoma County, CA has 11 federal disaster declarations on FEMA record (1964–2023). 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); Hurricane Katrina Evacuation (declared Sep 13, 2005, DR-3248). Counts include flood, severe storm, hurricane, and coastal storm declarations from the OpenFEMA DisasterDeclarationsSummaries dataset.

What is the flood risk grade for Sonoma County, CA?

Sonoma County is graded B (composite score 21/100, moderate risk). It ranks #152 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 Sonoma County?

147 NFIP flood insurance claims have been filed in Sonoma County, CA, totaling $3,994,861 in payouts. The average claim is $27,176. Source: FEMA FimaNfipClaims v2 dataset.

Has Sonoma County, CA had any recent flood disasters?

Yes. The most recent FEMA declaration affecting Sonoma County was Severe Winter Storms, Flooding, Landslides, and Mudslides on Mar 10, 2023 (DR-3592). The county has 11 declared disasters in the OpenFEMA record covering 1964–2023.

For this entity, the underlying data on this page comes from FEMA OpenFEMA datasets including the National Flood Hazard Layer and NFIP claims. The breakdown above is the federal record; the paragraphs below add the per-entity context that makes the headline numbers usable for a real decision rather than just a data lookup.

The methodology behind every numeric value on this page is publicly documented on the FEMA OpenFEMA datasets including the National Flood Hazard Layer and NFIP claims portal and described in detail on this site’s methodology page. Refresh cadence varies by underlying series; the page surfaces the as-of date for each number so readers can trace any figure back to the source release.

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.