FloodZoneMap.org

Sonoma County, California Flood Zones

Check an Address in Sonoma County

Enter any address in Sonoma County, California to see its FEMA flood zone

The Flooding Character of Sonoma County

Sonoma County experiences frequent flooding, with 244 flood events recorded in the last 30 years. Recent events include widespread impacts from a series of storm systems in December 2025, which disrupted holiday travel and caused power outages. Another significant event in November 2025 brought heavy rain and strong winds, leading to numerous flooding incidents across the region.

National Flood Insurance Program (NFIP) data shows a significant number of claims in Zone A, with an average payout of $18,486 and an average water depth of 8.9 feet. Zone X also shows a notable number of claims, with an average payout of $21,839 and an average water depth of 6.9 feet. Homeowners in coastal areas, as well as those in or near riverine floodplains, should pay particular attention to flood risk. Properties located in Zone A, which represents areas of higher flood risk, may warrant additional consideration.

Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.

Read First-Hand Flood Stories from Sonoma County

164 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.

Read California flood stories →

Flood Risk Data for Sonoma County

Sonoma County, California has recorded 312 flood-related events since 1996 according to NOAA's Storm Events Database, including 44 flash floods and 244 river or area floods. The county has received 36 federal disaster declarations, 10 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.

Sonoma County Disaster History

FEMA Disaster Declarations (1964–2023)

Disaster Declarations
36
Flood/Coastal Disasters
10
Latest Disaster
Severe Winter Storms, Flooding, Landslides, And Mudslides (2023-03-09)

Source: OpenFEMA Disaster Declarations Summaries.

Recent Disaster Declarations in Sonoma County

DeclarationTypeDate
Severe Winter Storms, Flooding, Landslides, And MudslidesFloodMar 9, 2023
Severe Winter Storms, Straight-line Winds, Flooding, Landslides, And MudslidesSevere StormFeb 21, 2023
Severe Winter Storms, Flooding, And MudslidesFloodJan 8, 2023
Severe Winter Storms, Flooding, Landslides, And MudslidesFloodDec 27, 2022
Glass FireFireSep 27, 2020
WildfiresFireSep 4, 2020
Lnu Lightning Fire ComplexFireAug 17, 2020
WildfiresFireAug 14, 2020
Covid-19BiologicalJan 20, 2020
Covid-19 PandemicBiologicalJan 20, 2020

Recorded Flood Events in Sonoma County

NOAA Storm Events Database (1996–2025)

Total Flood Events
312
River/Area Floods
244
Flash Floods
44
Coastal/Storm Surge
24
Total Property Damage
$222.8M
Flood Deaths
6
Flood Injuries
4

Source: NOAA National Weather Service Storm Events Database.

Recent Flood Events in Sonoma County

TypeDateDamage
FloodDec 26, 20250.00K
FloodDec 21, 20250.00K
FloodNov 17, 20250.00K
FloodNov 13, 20250.00K
FloodFeb 13, 20250.00K
FloodFeb 6, 20250.00K
FloodFeb 5, 20250.00K (1 deaths)
FloodFeb 5, 20250.01K
FloodFeb 4, 20250.00K (1 deaths)
FloodFeb 4, 20250.01K

Sonoma County Flood History

Flood — Dec 26, 2025

A series of storm systems impacted the Bay Area and Central Coast from December 19 to 25th, impacting Christmas holiday travel across the region. The most impactful systems arrived on Christmas Eve and Christmas Day. Two tornado warnings were issued for the coastal regions of San Mateo and Santa Cruz counties based off radar indicated rotation. San Francisco International Airport reported delay...

Flood — Dec 21, 2025

A series of storm systems impacted the Bay Area and Central Coast from December 19 to 25th, impacting Christmas holiday travel across the region. The most impactful systems arrived on Christmas Eve and Christmas Day. Two tornado warnings were issued for the coastal regions of San Mateo and Santa Cruz counties based off radar indicated rotation. San Francisco International Airport reported delay...

Flood — Nov 17, 2025

A low pressure system brought rain and winds to the Bay Area and Central Coast on November 16 and 17th. Special Marine Warnings and Special Weather Statements were issued due to isolated thunderstorms causing localized heavy rain and gusty winds. The main frontal rain band came through in the overnight hours, with isolated to scattered showers and some thunderstorms continuing into the 17th.

Flood — Nov 13, 2025

An rapidly intensifying low pressure system impacted the Bay Area and Central Coast on November 13, with the associated frontal systems and atmospheric river resulting in numerous flooding impacts and strong winds across the region. High Wind Warnings and Wind Advisories were issued throughout the Bay Area and Central Coast, with the High Wind Warnings focused on the immediate coastal areas. Ov...

Flood — Feb 13, 2025

A winter storm on February 13 caused widespread flooding and strong winds across the Bay Area and Central Coast.

Source: NOAA National Weather Service Storm Events Database.

Sonoma County NFIP Flood Insurance Claims

Total Claims Filed
6,133
Total Paid Out
$108.9M
Avg Claim
$21,019
Avg Water Depth
14.0 ft

Claims by Flood Zone

A Zones (High Risk)
5,174
V Zones (Coastal)
7
X Shaded (500-yr)
54
X Unshaded (Low)
303

Source: OpenFEMA NFIP Individual Claims (2.25M records analyzed).

Flood Zone Types in Sonoma County

FEMA assigns flood zone designations to areas in Sonoma County, California:

AE High Risk — 1% annual chance of flooding. Insurance required.

VE Very High Risk — Coastal flooding with wave action.

X (Shaded) Moderate Risk — 500-year floodplain.

X Low Risk — Outside major floodplains.

View all flood zone types →

Flood Insurance in Sonoma County

Properties in Sonoma County, California that are in FEMA-designated Special Flood Hazard Areas (zones A and V) with federally backed mortgages are required to carry flood insurance.

Even outside high-risk zones, flood insurance is recommended. From 2014 to 2024, nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area.

Visit FloodSmart.gov to find an agent and get a quote.