County Hazards

States › California › Sierra County

Sierra County, California

Recorded hazard history: storm events since 1950, federal disaster declarations since 1953, flood insurance claims since 1978, and FEMA's risk index.

FIPS 06091 · 3,283 residents (2021) · 953 sq mi · dominant hazard Other

Hail · 6Tornado · 0Flood · 3Wind · 1Winter · 0
1992-05-07: Hail1992-05-07: Hail2009-05-28: Hail2013-07-03: Hail2014-07-18: Hail2015-07-08: Hail2005-12-30: Flood2017-02-09: Flood2023-03-09: Flood2003-07-31: Wind
Sierra County within California. Dots: HailFloodWind event locations in the kept record. Boundaries: US Census Bureau.

NCEI notes that Storm Data is compiled from a variety of sources including the National Weather Service, other federal, state and local agencies, the media and the public; that property and crop damage figures are estimates; and that some events are recorded by NWS forecast zone rather than by county. FEMA notes that NFIP claim records are redacted and aggregated to protect the privacy of policyholders. NCEI storm records through 30 Jun 2026; OpenFEMA declarations refreshed 1 Oct 2026; NFIP claims as of 8 Sep 2026.

Between 1950 and 2026, NCEI recorded 60 storm events in Sierra County, California, led by other events.

That is 6.3 events per 100 square miles, below the California figure of 26.2, and 182.8 per 10,000 residents against 10.4 statewide.

2 events fall in the 12 months to 30 Jun 2026. NCEI attributes 1 death and 1 injury to events in the county, with property damage estimated at $9.4M.

FEMA has designated the county in 16 federal disaster declarations since 1953; the most recent is Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, And Mudslides (major disaster, 3 Apr 2023).

National Flood Insurance Program policyholders in the county filed 26 claims since 1978, of which 22 were paid, totalling $592K (about $27K per paid claim). FEMA counts 37 residential flood policies in force.

FEMA's National Risk Index rates the county's overall risk as "Very Low" and its expected annual loss as "Very Low" ($8.4M a year across 18 hazards).

2events, last 12 monthsto 30 Jun 2026
60events since 19501 death, 1 injury recorded
16disaster declarationslast 3 Apr 2023
26NFIP flood claims$592K paid

Compared with California and the United States

MeasureSierra CountyCaliforniaUS
Recorded events since 19506040,8491,977,440
Events per 100 square miles6.326.256.0
Events per 10,000 residents182.810.459.6
Events in the last 12 months21,23362,008
Deaths recorded by NCEI11,17026,435
Property damage (NCEI estimates)$9.4M$30B$575B
NFIP claims per 1,000 residents7.91.48.1
Average paid NFIP claim$27K$21K$43K
Claims per 100 policies in force, last 10 years18.95.016.1

County-recorded events plus zone-recorded events whose forecast zone is named for the county. State and US rows include events recorded only by forecast zone. Rates use 2021 Census population and land area.

Events by decade

Hail: 2Other: 1
Hail: 1Flood: 1Wind: 1Other: 8
Hail: 3Flood: 1Other: 26
Flood: 1Lightning: 1Other: 14
01950s01960s01970s01980s31990s112000s302010s162020s
Recorded events in Sierra County by decade and hazard group. HailFloodWindLightningOther NCEI recorded only tornadoes, hail and thunderstorm wind before 1996.

Trend: 49 events in the 20 years to 2025 against 11 in the 20 years before. Reporting practice changed in 1996 and again with automated reports in the 2000s, so decade totals measure the record as much as the weather.

Events by type

Other49
Hail6
Flood3
Wind1
Lightning1
HazardEventsDeathsShare of state's events
■ Other49—1.4%
■ Hail6—0.6%
■ Flood3—0.0%
■ Wind1—0.0%
■ Lightning110.3%

Hazard pages exist for hail, tornado, flood, wind and winter where the county has at least 10 recorded events. "Other" covers heavy rain, debris flow, dust, funnel clouds and similar reports.

Largest recorded events

DateEvent typeGroupMagnitudeProperty damageCrop damageDeathsInjuriesGeography
25 Jul 2020LightningLightning———11County
9 Feb 2017FloodFlood—$6.8M———County
11 Jan 2017Debris FlowOther—$1.6M———County
30 Dec 2005FloodFlood—$1.0M———County

Ranked by deaths, then injuries, then NCEI's damage estimate. Deaths and injuries are NCEI counts (direct plus indirect); no personal details are recorded here.

Federal disaster declarations

DeclaredNumberTypeIncidentTitlePrograms
3 Apr 2023DR-4699Major disasterSevere StormSevere Winter Storms, Straight-Line Winds, Flooding, Landslides, And MudslidesPublic assistance
10 Mar 2023EM-3592EmergencyFloodSevere Winter Storms, Flooding, Landslides, And MudslidesPublic assistance
22 Aug 2020DR-4558Major disasterFireWildfiresPublic assistance
22 Mar 2020DR-4482Major disasterBiologicalCovid-19 PandemicIndividual assistance, Public assistance
13 Mar 2020EM-3428EmergencyBiologicalCovid-19Public assistance
1 Apr 2017DR-4308Major disasterFloodSevere Winter Storms, Flooding, And MudslidesPublic assistance
14 Feb 2017DR-4301Major disasterSevere StormSevere Winter Storms, Flooding, And MudslidesPublic assistance
3 Feb 2006DR-1628Major disasterSevere StormSevere Storms, Flooding, Mudslides, And LandslidesPublic assistance
13 Sep 2005EM-3248EmergencyHurricaneHurricane Katrina EvacuationPublic assistance
4 Jan 1997DR-1155Major disasterSevere StormSevere Storms, Flooding, Mud And LandslidesIndividual assistance, Public assistance
12 Mar 1995DR-1046Major disasterSevere StormSevere Winter Storms, Flooding Landslides, Mud FlowIndividual assistance, Public assistance
3 Feb 1993DR-979Major disasterFloodSevere Winter Storm, Mud & Land Slides, & FloodingIndividual assistance, Public assistance
21 Feb 1986DR-758Major disasterFloodSevere Storms & FloodingIndividual assistance, Public assistance
20 Jan 1977EM-3023EmergencyDroughtDroughtPublic assistance
26 Jan 1969DR-253Major disasterFloodSevere Storms & FloodingIndividual assistance, Public assistance
24 Dec 1964DR-183Major disasterFloodHeavy Rains & FloodingIndividual assistance, Public assistance

Declarations in which FEMA designated this county, from the OpenFEMA Disaster Declarations Summaries (v2). DR: major disaster; EM: emergency; FM: fire management assistance. Programs show whether individual or public assistance was made available.

Flood insurance claims

197820022026
NFIP claims by year of loss in Sierra County, 1978 to 2026 (hover for the amount paid).
Claims since 197826
Paid claims22
Total paid$592K
Average paid claim$27K
Repetitive-loss properties0
Residential policies in force371.8% of 2,011 structures
Year of lossClaimsPaid claimsAmount paidAverage paid
201776$117,932$19,655
200576$383,321$63,887
199787$62,499$8,928
199632$28,513$14,256
199511$17$17

OpenFEMA NFIP claims (v3, as of 8 Sep 2026), aggregated by year of loss; amounts are building, contents and increased-cost-of-compliance payments as recorded. Repetitive-loss counts from the NFIP Multiple Loss Properties file (2 Aug 2026); policies in force from the NFIP Residential Penetration Rates file (3 Aug 2026).

National Risk Index

Overall riskVery Lowscore 31.5 of 100
Expected annual loss$8.4MVery Low
Social vulnerabilityRelatively High
Community resilienceRelatively Low
Hazard (NRI)Risk ratingExpected annual loss
Inland floodingRelatively Low$3,650,529
WildfireRelatively Moderate$3,485,422
EarthquakeRelatively Low$552,245
LightningRelatively Moderate$538,295
LandslideRelatively Moderate$97,489
DroughtRelatively Low$37,394
Winter weatherRelatively Low$28,578
Strong windVery Low$9,549
Heat waveVery Low$9,252
HailVery Low$5,617
TornadoVery Low$3,572
AvalancheVery Low$303
Volcanic activityVery Low$8

FEMA National Risk Index, December 2025 release. Ratings are FEMA's relative comparison of counties; expected annual loss is FEMA's modelled estimate of average yearly building, population and agriculture loss. See how to read the NRI.

Hurricane and tropical storm passes

No HURDAT2 track at tropical-storm strength passes within 100 miles of the county's centre point (through the 2025 season).

ZIP codes with flood claims

ZIP codes whose NFIP claims carry this county's code, with the number of claims. Five or more claims are needed for a ZIP page to be indexed.

Questions and answers

How often does it hail in Sierra County, CA?

NCEI records 6 hail events in Sierra County since 1950, in 5 different years; that is about 0.1 recorded events a year. 0 reports were golf-ball size (1.75 in) or larger.

Has Sierra County had a tornado?

NCEI records no tornado in Sierra County since 1950.

When was the last federal disaster declaration for Sierra County?

3 Apr 2023: Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, And Mudslides, a major disaster declaration for severe storm. The county appears in 16 declarations since 1953.

How many flood insurance claims have been filed in Sierra County, and how much was paid?

26 NFIP claims since 1978, 22 of them paid, for $592K in total. FEMA publishes these figures redacted and aggregated; individual properties are not identified.

Is Sierra County in the National Risk Index's high-risk band?

FEMA's National Risk Index (December 2025) rates the county "Very Low" for overall risk, "Very Low" for expected annual loss, "Relatively High" for social vulnerability and "Relatively Low" for community resilience. These ratings are FEMA's relative comparison across all US counties.

How does Sierra County compare with the rest of California?

6.3 recorded events per 100 square miles against 26.2 statewide, and 7.9 NFIP claims per 1,000 residents against 1.4. The comparison table on this page shows each measure beside the state and national figures.

Provenance

Storm events: NOAA NCEI Storm Events Database, yearly details files through 30 Jun 2026 (public domain). Declarations: OpenFEMA DisasterDeclarationsSummaries v2, refreshed 1 Oct 2026. Flood claims: OpenFEMA NfipClaims v3 as of 8 Sep 2026; NfipMultipleLossProperties v1 (2 Aug 2026); NfipResidentialPenetrationRates v1 (3 Aug 2026). Risk index: FEMA National Risk Index, December 2025. Hurricane tracks: NHC HURDAT2 through 2025. Population and area: US Census Bureau, 2021 vintage. Built 1 Oct 2026; see the methodology and corrections pages. Hazard hubs: Hail · Tornado · Flood · Wind · Winter.