San Mateo County, California severe weather history spans 163 recorded events between 1958 and 2026. The dominant hazard is flood, accounting for 39.3% of all recorded events. It ranks #2,646 nationally and #27 in California.
163
Recorded events
2
Direct deaths
20
Direct injuries
$13.9M
Property damage
The record
What the San Mateo County, California severe weather history record shows
Across the archive, San Mateo County, California severe weather history averages 2.4 recorded events a year. The busiest stretch on record is the 2010s, with 75 events logged in that decade alone. Roughly 4 events fall before 1990 and 159 from 1990 onward — a gap that reflects the expansion of NOAA reporting practice as much as the weather itself.
The deadliest hazard in the San Mateo County, California record is flash flood, responsible for 1 direct deaths. The costliest is flood, with $10.1M in reported property damage. In total, 8 distinct hazard types appear in this county archive, each listed with its own dated record below.
By hazard type
Every hazard type recorded in San Mateo County
| Hazard | Events | Deaths | Damage | Max | Span |
|---|---|---|---|---|---|
| Flood | 64 | 0 | $10.1M | 0 | 1996–2026 |
| Flash Flood | 32 | 1 | $808K | 0 | 1997–2026 |
| Thunderstorm Wind | 20 | 0 | $60K | 84 | 1980–2025 |
| Debris Flow | 18 | 0 | $0 | 0 | 2017–2023 |
| Heavy Rain | 12 | 1 | $2.2M | F0 | 1996–2024 |
| Hail | 9 | 0 | $30 | 0.25 | 2017–2024 |
| Tornado | 4 | 0 | $825K | F1 | 1958–2005 |
| Lightning | 4 | 0 | $0 | 0 | 2017–2020 |
Decade by decade
San Mateo County, California severe weather history by decade
Reporting practice changed over time — early decades are undercounted, not calmer.
Tornado tracks
Paths crossing this county
2 mapped tornado paths intersect this county: 2 touched down inside it and 0 crossed in from a neighbouring county. This comes from path geometry, not county-tagged reports.
| Date | Scale | Deaths | Injuries | Path length | Origin |
|---|---|---|---|---|---|
| 2005-03-20 | EF1 | 0 | 0 | 3.0 mi | Touched down here |
| 1998-02-07 | EF0 | 0 | 0 | 0.2 mi | Touched down here |
Significant events
Deadliest events on record in San Mateo County
| Date | Type | Location | Deaths | Injuries | Damage |
|---|---|---|---|---|---|
| Jan 11, 1998 | Heavy Rain | SAN MATEO | 1 | 0 | $0 |
| Feb 3, 1997 | Flash Flood | LOMA MAR | 1 | 0 | $0 |
| Jan 2, 1998 | Heavy Rain | SAN MATEO | 0 | 12 | $0 |
| Mar 14, 2012 | Heavy Rain | PACIFICA | 0 | 5 | $50K |
| Oct 13, 2009 | Heavy Rain | MONTARA | 0 | 3 | $0 |
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
Heavy rain caused flooding of several trailer parks in Redwood City. The combination of standing water and a local creek flooding resulted in the need for residents to be evacuated from the Le Mar Trailer Park and RC Mobile Home Park on E Bayshore in Redwood City. 50 mobile homes were evacuated and residents were sent to shelters.
This powerful rainstorm overwhelmed pipes and manholes in San Mateo, San Carlos and Millbrae causing over 127,000 gallons of untreated sewage to flow into the streets and creeks. Over 55,000 gallons made it all the way to the San Francisco Bay.
Two accidents shut down Highway 1 for brief periods. One occurred on March 14 which was a head-on crash just south of Devil's Slide. Two sedans were involved with minor injuries to the two drivers. The other occurred on March 16 when two trucks collided at 10:45 am west of the turnoff for Ox Mountain landfill. Three riders suffered minor cuts and bruises.
Context
Risk, population and federal disasters
Relatively High
FEMA NRI risk rating
742,340
Population (ACS)
$1.6M
Median home value
24
Federal declarations
| Declared | Incident | Title | Type |
|---|---|---|---|
| Apr 3, 2023 | Severe Storm | SEVERE WINTER STORMS, STRAIGHT-LINE WINDS, FLOODING, LANDSLIDES, AND MUDSLIDES | DR |
| Mar 10, 2023 | Flood | SEVERE WINTER STORMS, FLOODING, LANDSLIDES, AND MUDSLIDES | EM |
| Jan 14, 2023 | Flood | SEVERE WINTER STORMS, FLOODING, LANDSLIDES, AND MUDSLIDES | DR |
| Jan 9, 2023 | Flood | SEVERE WINTER STORMS, FLOODING, AND MUDSLIDES | EM |
| Aug 22, 2020 | Fire | WILDFIRES | DR |
| Aug 20, 2020 | Fire | CZU LIGHTNING FIRE COMPLEX | FM |
Quick answers
Frequently asked
How many severe weather events have been recorded in San Mateo County, California?
163 events are on record between 1958 and 2026, causing 2 direct deaths and $13.9M in property damage.
What is the most common severe weather hazard in San Mateo County?
Flood, with 64 recorded events — 39.3% of everything in the archive for this county.
How many tornadoes have crossed San Mateo County?
2 mapped tornado paths intersect the county boundary; 2 of them touched down inside it. This is derived from path geometry, not county-tagged reports.
How many federal disaster declarations cover San Mateo County?
24 federal disaster declarations from FEMA include San Mateo County, each tied to a specific incident period.
How risky is San Mateo County compared with the rest of the country?
FEMA's National Risk Index rates San Mateo County as relatively high risk, placing it in the 99 percentile of its state for expected annual loss.
Where does the San Mateo County, California severe weather history data come from?
Every figure is drawn from United States federal public-domain records: NOAA/NCEI Storm Events for the event archive, NOAA SPC SVRGIS for mapped tornado paths, FEMA for disaster declarations and risk ratings, and the U.S. Census for population context. Dates are shown in UTC and recent entries may still be revised by NOAA.
Nearby
Neighbouring counties
- San Luis Obispo County 83
- Santa Barbara County 162
- San Joaquin County 116
- Santa Clara County 264
- San Francisco County 135
- Santa Cruz County 201
Cite this page
“San Mateo County, California.” Severe Weather History. severeweatherhistory.com/county/california/san-mateo-county/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.