Sierra County, California
Natural disaster risk, federal disaster history and flood insurance facts.
Sierra County, California has a very low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 68% of US counties. It ranks 57th of 58 counties in California. The costliest hazards here are inland flooding, wildfires and earthquakes. FEMA estimates about $8.4 million a year in expected losses, or roughly $2,631 per resident. Since 1964 it has been included in 14 federal disaster or emergency declarations for natural events (11 major disasters). The most recent was in April 2023 (severe winter storms, straight-line winds, flooding, landslides and mudslides). Only 37 homes here carry federal flood insurance. Since 1978, federal flood insurance has paid about $590,000 on 26 claims here.
FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.
Top risks in Sierra County
- Check the FEMA flood map for your address, and ask the seller or landlord about past flooding.
- Price a flood policy now. Most new federal policies take 30 days to start.
- Clear dry plants and debris within 5 feet of the house.
- Get home insurance quotes early; availability varies by area.
- Ask whether an older house is bolted to its foundation.
- Consider separate earthquake insurance where risk is high.
All 18 hazards
What the ratings mean ›| Hazard | Rating | Score | Expected loss a year | |
|---|---|---|---|---|
| Inland flooding | 37.7 | $4M | ||
| Wildfire | 95.6 | $3M | ||
| Earthquake | 66.8 | $552K | ||
| Lightning | 77.6 | $538K | ||
| Landslide | 94.6 | $97K | ||
| Drought | 35.9 | $37K | ||
| Winter weather | 33.2 | $29K | ||
| Strong wind | 2.4 | $10K | ||
| Heat wave | 7.5 | $9K | ||
| Hail | 3.4 | $6K | ||
| Tornado | 2.4 | $4K | ||
| Avalanche | 44.9 | $303 | ||
| Volcanic activity | 45.9 | $8 |
Scores are percentiles: a score of 90 means higher risk than about 90% of US counties for that hazard. Hazards FEMA does not rate here are left out. Social vulnerability is relatively high and community resilience is relatively low in FEMA's measures.
Federal disaster history
Recent disasters nationwide ›Declarations by decade
Federal declarations for natural events that included Sierra County. 2020s bar runs to November 2026.
By type
Most recent
Show all 14
California also had 35 statewide declarations that did not name single counties.
Storm history since 1992
Tornado risk by county ›The National Weather Service has logged 60 storm reports in Sierra County since 1992, with 1 death and 1 injury and about $9.4 million in reported damage. No tornadoes are on record here.
Most damaging storms
| Date | Type | Near | Damage |
|---|---|---|---|
| Feb 9, 2017 | Flood | Sattley | $7M |
| Jan 11, 2017 | Debris Flow | Pike | $2M |
| Dec 30, 2005 | Flood | Sierraville | $1M |
| Jul 25, 2020 | Lightning | Sierraville Drwtr Ar | 1 killed |
Source: NOAA Storm Events Database, county-based reports through Aug 26, 2025. Tornado records start in 1950, hail and wind in 1955, and floods and other storm types in 1996, so older decades undercount. Damage is in dollars of the year it happened and is often an estimate. Winter storms, heat and hurricanes are logged by forecast zone, not county, so they are not counted here.
Flood insurance in Sierra County
Check your address flood zone ›National Flood Insurance Program (NFIP) records only; private flood policies are not included. Home counts as of Aug 3, 2026. Since 2021 NFIP prices each home separately under Risk Rating 2.0, so your price depends on the building, not the county. Ask an agent for a quote.
Homes in Sierra County
Older homes and mobile homes usually suffer more damage in storms, floods and earthquakes, and can cost more to insure. If you are buying, ask about roof age, foundation bolting and any retrofits. Source: US Census Bureau, American Community Survey 2020 to 2024 5-year estimates; 2,120 housing units.
Compare in California
All 58 ›| Largest counties | Overall risk | Top hazard |
|---|---|---|
| Los Angeles County | Earthquake | |
| San Diego County | Inland flooding | |
| Orange County | Earthquake | |
| Riverside County | Inland flooding | |
| San Bernardino County | Inland flooding | |
| Santa Clara County | Earthquake | |
| Alameda County | Earthquake | |
| Sacramento County | Inland flooding |
Neighboring counties
| County | Overall risk | Declarations |
|---|---|---|
| Washoe County, NV | 52 | |
| Nevada County | 21 | |
| Yuba County | 26 | |
| Lassen County | 17 | |
| Plumas County | 21 |
Common questions about Sierra County
What is the biggest natural hazard in Sierra County?
Inland flooding has the highest expected yearly losses in Sierra County, about $3.7 million a year in FEMA's estimate. Wildfire is second at $3.5 million.
How many federal disasters has Sierra County had?
Sierra County has been included in 14 federal disaster or emergency declarations for natural events since 1964, including 11 major disasters. The most recent was Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides in April 2023.
Is Sierra County a high-risk place to live?
Its overall rating is Very Low, 57th highest of 58 in California. A county rating covers the whole area. Risk at one address can be much higher or lower, so check the FEMA flood map and ask about the home's history.
Do I need flood insurance in Sierra County?
Standard home insurance does not cover flooding. About 1 in 56 homes in Sierra County has federal flood insurance. Lenders require it in mapped high-risk zones, but many flood claims come from outside those zones.
How many tornadoes has Sierra County had?
NOAA records list 0 tornadoes in Sierra County since 1950. The weather service has also logged 6 hail reports and 3 floods here.
Sources: FEMA National Risk Index (December 2025), OpenFEMA Disaster Declarations Summaries, and NFIP policy and claims data. Hazard Compass is independent and not affiliated with FEMA. These figures describe the whole county, not a single property, and are not insurance or safety advice. Report a problem.