County storm facts
Storm prep for San Mateo County residents
San Mateo County has had 1,110 flood insurance claims since 1978, 18 federal disaster declarations for fires, storms, floods or mudslides since 1982, and 1 mapped wildfires that started here since 2021.
Sources:
Local data from official sources, updated weekly. This snapshot: September 29, 2026. Alerts load live from the National Weather Service when you open this page.
Active alerts now
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Source: National Weather Service alerts.
Forecasts for this county (NWS county zone CAC081) come from:
Source: National Weather Service (the exact query), data as of September 29, 2026.
Help right now
Live from FEMA and the Red Cross shelter list. Check your address on the home page for what’s nearest you.
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FEMA assistance
Open shelters
Evacuation status
Live evacuation status isn’t shown here yet. Your county’s evacuation map has the current orders and warnings.
Road conditions
Closures, chain controls and incidents on state highways.
Recent burn areas
1 fires that started in San Mateo County since January 1, 2021 have a mapped perimeter, covering 27 acres in all.
Largest
| Fire | Year | Acres |
|---|---|---|
| Whipple | 2023 | 27 |
Acres are each fire’s whole mapped area, which can reach past the county line.
Burned hillsides can’t soak up heavy rain, so mud and debris can rush downhill with little warning.
Source: NIFC WFIGS Interagency Fire Perimeters (the exact query), data as of September 29, 2026.
Flood history
1,110 flood insurance claims have been filed in San Mateo County since 1978. 220 of them were for floods from 2017 to 2026.
The years with the most claims: 1998 (236), 1982 (156), 2022 (97).
This is history, not a prediction. These are National Flood Insurance Program claims, so they only count insured buildings.
FEMA’s data runs through September 8, 2026.
Source: FEMA OpenFEMA, NFIP Redacted Claims (the exact query), data as of September 29, 2026.
Federal disaster declarations
San Mateo County has been part of 18 federal disaster declarations for fires, storms, floods or mudslides since 1982: 3 for fires and 15 for storms, floods or mudslides.
Most recent
- Severe Winter Storms, Straight-line Winds, Flooding, Landslides, and MudslidesApril 3, 2023 · DR-4699-CA
- Severe Winter Storms, Flooding, Landslides, and MudslidesMarch 10, 2023 · EM-3592-CA
- Severe Winter Storms, Flooding, Landslides, and MudslidesJanuary 14, 2023 · DR-4683-CA
FEMA’s ids start with DR for a major disaster, EM for an emergency and FM for fire management.
Source: FEMA OpenFEMA, Disaster Declarations Summaries (the exact query), data as of September 29, 2026.
Coast and tsunami
The California Geological Survey maps tsunami hazard areas in San Mateo County. If you live, work or travel near the coast or bay shore, check whether your address is in one.
CGS tsunami hazard maps for San Mateo County
Source: California Geological Survey tsunami hazard areas (the exact query), data as of September 29, 2026.
Rain in past strong El Niño winters
We haven’t verified a long-record NOAA weather station for San Mateo County yet, so there’s no local chart here. See past strong El Niño winters in Los Angeles, San Diego and San Francisco.
Local help
Alerts sign-up, free sandbags, evacuation zones and help lines for this county.
- Emergency management officeSan Mateo County Department of Emergency Management (opens in a new tab)
- Alerts sign-upSMC Alert (opens in a new tab)
- Evacuation mapGenasys Protect (opens in a new tab)
- SandbagsSan Mateo County sandbags (opens in a new tab)
- Help finding food, shelter and other services211 California (opens in a new tab)Call 211
Power and internet outages
Power
- Outage mapPacific Gas & Electric (PG&E) (opens in a new tab)
- Planned power shutoffs (PSPS)CPUC Public Safety Power Shutoff resources (opens in a new tab)
Internet and phone
- Carrier statusAT&T outage map (opens in a new tab)
- Carrier statusSpectrum service status (opens in a new tab)
- Regional internet outagesCloudflare Radar — internet outages (opens in a new tab)
4 more we haven’t verified: search for them by name
- Carrier statusVerizon outage/status
- Carrier statusT-Mobile service status
- Carrier statusXfinity/Comcast support
- Carrier statusFrontier outage map
What about your street?
County numbers can’t tell you about your home. Check your address against the official flood, fire, landslide and tsunami maps.