421 flood insurance claims·$8.2M paid·12 federal flood & hurricane disasters
Share of the whole county outline, rivers and lakes included; parts FEMA hasn’t mapped count as zero.
Shaded areas are FEMA’s mapped flood hazard zones in and around San Joaquin County, California. Zoomed out they are simplified; at street level the map switches to FEMA’s exact layer. Tap anywhere to check that spot, or search an address above.
River and roadway flooding driven by winter storms and atmospheric rivers dominates San Joaquin County. Over the last 30 years, the NOAA Storm Events Database recorded 53 standard floods resulting in two deaths, alongside 4 flash flood events.
Recent impacts are illustrated by events in February 2025 and November 2025. A winter storm from February 3rd through 5th brought 2 to 5 inches of rain to the Valley and foothills alongside heavy mountain snow, causing roadway flooding, road closures on Highway 99, and multiple search and rescue efforts. A subsequent winter storm from February 12th to 14th produced 1 to 6 inches of rain and flooded roads, while an atmospheric river from November 12th through 14th dropped 1 to 4 inches of rain, resulting in widespread roadway flooding.
NFIP claim data shows historical payouts across multiple zones. Zone A accounts for 198 claims with an average payout of $32,834 and an average recorded water depth of 12 inches. Zone X accounts for 104 claims averaging $33,101 with an average water depth of 20 inches, including 57 claims in shaded areas (averaging $21,449 and an average 8-inch depth) and 48 claims in unshaded areas (averaging $36,978 and an average 5-inch depth). Property owners in Zone A and Zone X should pay the closest attention to these risks.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
35% of San Joaquin County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
303 NFIP claims with a recorded rated flood zone, 1978 to date. The zone is the one FEMA used to rate that policy, which may not match today’s map. Source: OpenFEMA NFIP claims.
In flood insurance claims here that reported a flood depth, the average was 12 inches.
Drawn to scale against an 80-inch door. Even a few inches soaks flooring, the bottom of the drywall and anything plugged in near the floor.
Average of the depths reported on claims (zero and implausible values left out); FEMA’s record doesn’t say exactly where each depth was measured. Source: OpenFEMA NFIP claims.
The worst year was 1997, with 80 claims and $2.6M paid.
Bar height is scaled by square root so ordinary years stay visible next to the worst one. NFIP claims by year of loss. Source: OpenFEMA.
29 NOAA storm reports from San Joaquin County describe what happened, in the words of the forecasters who covered it. Read the California flood stories →
25 federal disaster declarations since 1964, 12 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Winter Storms, Flooding, Landslides, And Mudslides | Mar 9, 2023 |
| Severe Winter Storms, Straight-line Winds, Flooding, Landslides, And Mudslides | Feb 21, 2023 |
| Severe Winter Storms, Flooding, And Mudslides | Jan 8, 2023 |
| Severe Winter Storms, Flooding, Landslides, And Mudslides | Dec 27, 2022 |
| Severe Winter Storms, Flooding, And Mudslides | Feb 1, 2017 |
| Severe Storms, Flooding, Landslides, And Mudslides | Mar 29, 2006 |
| Severe Storms, Flooding, Mudslides, And Landslides | Dec 17, 2005 |
| Hurricane Katrina Evacuation | Aug 29, 2005 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
57 since 1996: 4 flash floods and 53 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flood | Dec 25, 2025 | — |
| Flood | Nov 16, 2025 | — |
| Flood | Nov 13, 2025 | — |
| Flood | Feb 13, 2025 | — |
| Flood | Feb 4, 2025 | — |
| Flood | Jan 22, 2024 | — |
| Flood | Feb 20, 2024 | — |
| Flood | Mar 19, 2023 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
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 across the Valley, foot…
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 inches in the mount…
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 estimated to have fallen at…
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 mud and rocks in so…
National Weather Service narratives, lightly trimmed. Source: NOAA Storm Events Database.
Every colour on the map above is a place on this drawing: where the ground sits relative to the flood FEMA plans for.
If a building in San Joaquin County is in a high-risk zone (A or V) and its mortgage comes from a federally regulated or insured lender, or is federally backed, flood insurance is required.
Outside those zones it is optional, and often worth having: from 2014 to 2024 nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area. Since Risk Rating 2.0, NFIP premiums are set for each building, so the only reliable price is a quote: FloodSmart.gov or a local agent.