Trinity County, CA Environment & Hazard Risk
Relatively Low natural hazard risk, led by landslide. 200 storm events since 1996.
- Expected yearly loss
- $29.1M
- Relatively Low nationally
- Storm events since 1996
- 200
- Most often winter weather
- Flood insurance policies
- 55
- 0.7% of homes
- Hurricanes nearby
- 0
- Since 1851
Natural hazard risk
FEMA National Risk Index, December 2025
Overall risk
Relatively Low
Score 79.5 of 100
Social vulnerability
Very High
Score 82.6 of 100
Community resilience
Relatively Low
Score 37.0 of 100
Community resilience runs the other way: a higher rating means a community can recover faster.
Building value exposed: $4.1B · Agriculture value exposed: $9.4M · Risk-adjusted yearly loss: $43M
Risk by hazard
- LandslideRelatively High$730K/yr expected annual loss, about 18 events a year
- WildfireRelatively High$13M/yr expected annual loss, about once every 39 years
- EarthquakeRelatively Low$2M/yr expected annual loss, about once every 29 years
- Volcanic activityVery Low$14/yr expected annual loss, about once every 833 years
- AvalancheVery Low$630/yr expected annual loss, about once every 100 years
- Heat waveRelatively Low$161K/yr expected annual loss, about 4.8 events a year
- LightningVery Low$27K/yr expected annual loss, about 9.6 events a year
- Winter weatherVery Low$4,148/yr expected annual loss, about 24 events a year
- HailVery Low$9,463/yr expected annual loss, about once every 11 years
- TornadoVery Low$11.4K/yr expected annual loss, about once every 30 years
- Strong windVery Low$3,775/yr expected annual loss, about once every 73 years
Bars show the national percentile score (0 to 100) for each hazard. Dollar figures are expected annual losses to buildings, people and crops. Not rated here: coastal flooding, cold wave, drought, hurricane, ice storm, riverine flooding, tsunami.
Flood risk and insurance
National Flood Insurance Program and FEMA flood maps
Check the flood zone for an address
- Homes with flood insurance
- 55 of 7,647 (0.7%)
- Homes in high-risk flood zones
- 269
- Insured in high-risk zones
- 40 (15%)
- Flood claims since 1978
- 23
- Claims paid since 1978
- $72.6K
Flood claims paid per year
- Flooding$52.9K · 19 claims
- Pineapple Express - Southern$0 · 1 claim
Storm history
Since 1996: 200 events, 0 deaths, $40M in damage
- Winter Weather83
- Heavy Rain36
- Heavy Snow30
- Hail18
- Winter Storm13
- Wildfire6
- Flood4
- Flash Flood3
- High Wind2
- Thunderstorm Wind2
Events per year
Most damaging storms
Since 1996, ranked by deaths, injuries and damage
- Wildfire09/01/2020
Southern Trinity
$27.2M damage
What happened
At least 302 structures were destroyed in southern Trinity County during September due to episodic active fire behavior associated with the August Complex.
- Heavy Rain02/09/2017
Hyampom, Trinity County
$4M damage
What happened
Culvert failures and slipouts along Highway 36 in Trinity County from mile post 2 to 14.
- Wildfire08/28/2001
Weaverville, Trinity County
$3.5M damage
What happened
A car on Highway 299 sparked the blaze near Oregon Mountain summit that was fanned by strong winds. Final fire size was about 1680 acres. Two-thirds of Weaverville's 3,000 residents were evacuated for a time. Thirteen homes, thirteen outbuildings, and 29 vehicles were destroyed.
- Flash Flood10/22/2021
Carrville, Trinity County
$3.2M damage
What happened
An atmospheric river aided in heavy rain development across the River Complex burn scar. One or possibly more debris flows occurred as a result. Removal, protective measures, and repair costs from this debris flow are estimated to be $3.2 million.
- Wildfire10/01/1999
Denny, Trinity County
$1.3M damage
What happened
Megram Fire started by lightning in August, fanned by high winds in September was knocked down by rain in October so that firefighters could bring it under control. Dense smoke forced the evacuation of thousands of residents of the Hoopa and Willow Creek areas. Visibility was often less than 150 feet. Smoke and ashes spread over much of Northwest California. $75 million was spent on firefighting, $1.3 million in damage to commercial timber, $16 million potential damage to fisheries and $6.2 million needed for rehabilitation for a total cost of $98.5 million. This was the fifth largest fire (acreage) in California history with 141,200 acres burned. No fatalities or injuries was directly caused by weather.
- Heavy Rain01/17/2017
Hayfork, Trinity County
$750K damage
What happened
Undermined hill and slip-out near mile post 15 on Highway 3.
Drinking water
17 community water systems serve about 9,293 people. Violations since 2021.
11 systems had health-based violations, such as a contaminant over the legal limit or a missed treatment step. 12 systems had a violation of any kind still open at last report.
- Weaverville C.s.d.Serves 3,975 · Surface water · Local government1 health violation
- Trinity Co. W.w. Dist #1Serves 2,324 · Surface water · Local governmentNo health violations+1 monitoring or reporting
- Trinity Center M.w.c.Serves 729 · Surface water · PrivateNo health violations+1 monitoring or reporting
- Lewiston Community Services DistrictServes 677 · Surface water · Private1 health violation+1 monitoring or reporting
- Trinity Village Mutual WaterServes 330 · Surface water · PrivateNo health violations
- Salyer Mutual Wc (Formerly Riverview Ac)Serves 231 · Surface water · Private1 health violation+2 monitoring or reporting
- Pine Cove Rv ParkServes 223 · Groundwater · Private1 health violation+2 monitoring or reporting
- Trinity Knolls Mutual Water CompanyServes 138 · Groundwater · Private1 health violation+2 monitoring or reporting
Largest systems by population served. Monitoring and reporting violations mean required tests or notices were late or missing, not that the water was unsafe.
Climate
1991-2020 normals at Big Bar 4 E, 5.9 mi from the county center
Summer highs peak around 97°F in Jul and winter lows bottom out near 34°F in Dec. About 35.8 inches of rain falls in a typical year, with 2.7 inches of snow.
| Month | High | Low | Rain | Snow |
|---|---|---|---|---|
| Jan | 50°F | 34°F | 6.41 in | 0.7 in |
| Feb | 56°F | 35°F | 5.37 in | 0.4 in |
| Mar | 62°F | 37°F | 4.58 in | 0.3 in |
| Apr | 69°F | 39°F | 2.62 in | - |
| May | 78°F | 44°F | 1.67 in | - |
| Jun | 86°F | 48°F | 0.73 in | - |
| Jul | 97°F | 53°F | 0.17 in | - |
| Aug | 95°F | 52°F | 0.20 in | - |
| Sep | 89°F | 47°F | 0.44 in | - |
| Oct | 74°F | 41°F | 2.20 in | - |
| Nov | 57°F | 38°F | 4.19 in | 0.2 in |
| Dec | 48°F | 34°F | 7.24 in | 1.1 in |
| Year | 57°F average | 35.8 in | 2.7 in | |
Pollution sites
0 Superfund sites and 0 toxic release facilities in Trinity County
No Superfund sites or toxic release facilities in Trinity County in our data.
Superfund sitesToxic release facilitiesEPA inspections and enforcementAir toxics cancer risk1 historic places
Frequently asked questions
- How risky is Trinity County for natural disasters?
- FEMA rates Trinity County relatively low for overall natural hazard risk, with expected losses of $29.1M a year. The highest-rated hazards are landslide (relatively high), wildfire (relatively high), earthquake (relatively low).
- What storms are most common in Trinity County?
- Since 1996, NOAA recorded 200 storm events affecting Trinity County, most often winter weather (83), heavy rain (36), heavy snow (30).
- How many homes in Trinity County have flood insurance?
- 55 residential flood insurance policies are in force in Trinity County, covering about 0.7% of homes. The program has paid $72.6K on 23 claims here since 1978.
- What is the weather like in Trinity County?
- At Big Bar 4 E, average highs reach 97°F in Jul and lows fall to 34°F in Dec, with 35.8 inches of rain a year (1991-2020 normals).
Source: FEMA (National Risk Index, NFIP), NOAA (Storm Events, HURDAT2, Climate Normals), EPA · Last updated 08/01/2026 · Storm counts include events in forecast zones that touch the county. This product uses the FEMA OpenFEMA API, but is not endorsed by FEMA.