Enter any address in San Joaquin County, California to see its FEMA flood zone
River and roadway flooding from winter storms is the dominant flood character in San Joaquin County. Recent events include widespread flooding and road closures in February 2025 following a strong winter storm, and similar conditions in December 2025 due to prolonged wet weather and heavy snowfall in the Sierra Nevada.
Homeowners in Zone A, which has seen the most NFIP claims and significant water depths, should pay close attention. Properties in Zone X_UNSHADED also have a high average payout and water depth, indicating potential for substantial damage.
Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.
29 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
San Joaquin County, California has recorded 57 flood-related events since 1996 according to NOAA's Storm Events Database, including 4 flash floods and 53 river or area floods. The county has received 25 federal disaster declarations, 12 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.
FEMA Disaster Declarations (1964–2023)
Source: OpenFEMA Disaster Declarations Summaries.
| Declaration | Type | Date |
|---|---|---|
| Severe Winter Storms, Flooding, Landslides, And Mudslides | Flood | Mar 9, 2023 |
| Severe Winter Storms, Straight-line Winds, Flooding, Landslides, And Mudslides | Severe Storm | Feb 21, 2023 |
| Severe Winter Storms, Flooding, And Mudslides | Flood | Jan 8, 2023 |
| Severe Winter Storms, Flooding, Landslides, And Mudslides | Flood | Dec 27, 2022 |
| Covid-19 | Biological | Jan 20, 2020 |
| Covid-19 Pandemic | Biological | Jan 20, 2020 |
| Severe Winter Storms, Flooding, And Mudslides | Flood | Feb 1, 2017 |
| Severe Storms, Flooding, Landslides, And Mudslides | Severe Storm | Mar 29, 2006 |
| Severe Storms, Flooding, Mudslides, And Landslides | Severe Storm | Dec 17, 2005 |
| Hurricane Katrina Evacuation | Hurricane | Aug 29, 2005 |
NOAA Storm Events Database (1996–2025)
Source: NOAA National Weather Service Storm Events Database.
| Type | Date | Damage |
|---|---|---|
| Flood | Dec 25, 2025 | 0.00K |
| Flood | Nov 16, 2025 | 0.00K |
| Flood | Nov 13, 2025 | 0.00K |
| Flood | Feb 13, 2025 | 0.00K |
| Flood | Feb 4, 2025 | 0.00K |
| Flood | Jan 22, 2024 | 0.00K |
| Flood | Feb 20, 2024 | 0.00K |
| Flood | Mar 19, 2023 | 0.00K |
| Flood | Dec 18, 2023 | 0.00K |
| Flood | Jan 15, 2023 | 0.00K |
Flood — Dec 25, 2025
A prolonged period of wet weather brought heavy snowfall and strong winds to the Sierra Nevada. Heaviest snowfall was observed from 12/24-12/26 when snow levels came down below the mountain passes. Snowfall measurements over the 12/24-12/26 timeframe were around 2-5 ft per Caltrans, Ski resorts, and UC Berkeley Central Sierra Snow Lab. Southerly wind gusts of 50-80 mph were observed as well acr...
Flood — Nov 16, 2025
A secondary wave of precipitation brought additional rain, wind and light mountain snow from November 16th through November 17th. This led to additional flooding impacts in the Valley and foothills. 1 to 3 inches of rain were observed over this two day timeframe across most of the area, except in Shasta County where 2 to 5 inches were observed. There were also snow measurements of around 3 to 8...
Flood — Nov 13, 2025
An Atmospheric River in the middle of November brought light mountain snow, widespread rainfall with roadway flooding, gusty winds, and thunderstorms from November 12th through November 14th. Around 1 to 4 inches of rain were observed across interior northern California over this 48 hour period. Gusty southerly winds of 25 to 65 mph were also observed as well. 4 to 12 inches of snow was estimat...
Flood — Feb 13, 2025
A strong winter storm from late February 12th into Friday, February 14th brought heavy snow, rain, and gusty winds. This brought from 1 to 6 inches of rain, with totals of 2 to nearly 4 feet of heavy snow above 4500 feet. Gusty southerly wind gusts of 25 to 50 mph in the Valley, 40 to 60 mph in the mountains and foothills were recorded. Roads were reported to be flooded, as well as covered with...
Flood — Feb 4, 2025
A strong winter storm brought heavy mountain snow, moderate to heavy rain with river and roadway flooding, and gusty southerly winds February 3rd through 5th. Multiple feet of heavy snow were observed above 5000 feet, with 2 to 5 inches of rain observed in the Valley and foothills and southerly wind gusts of up to 50 mph. There were numerous reports of flooding in the Valley that led to multipl...
Source: NOAA National Weather Service Storm Events Database.
Source: OpenFEMA NFIP Individual Claims (2.25M records analyzed).
FEMA assigns flood zone designations to areas in San Joaquin 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.
Properties in San Joaquin 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.