Siskiyou County, California Natural Disaster Risk
FEMA National Risk Index assessment · CA
MediumComposite Risk Score
National percentile: 89th
Siskiyou County faces medium composite natural disaster risk (NRI Risk Index score 89.0, 89th national percentile), driven primarily by drought and wildfire exposure. Expected annual loss across all 18 hazard types is $57M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Siskiyou County carries a medium composite natural disaster risk, with a National Risk Index score of 89.0 out of 100 — placing it in the 89th national percentile and near the national midpoint for natural-disaster risk. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
The county's risk is driven primarily by drought (extended dry periods that stress water supplies and agriculture) at High risk — $5M in expected annual loss and about 73.65 events per year; wildfire (uncontrolled fires that spread across wildland and into communities) at High risk — $14M in expected annual loss and about 0.01 events per year; and volcanic activity (eruptions producing ashfall, lava, and pyroclastic hazards) at High risk — $2M in expected annual loss and about 0.00 events per year. Across all hazards, FEMA estimates $57M in expected annual loss for a population of 44K.
Beyond physical exposure, Siskiyou County has a high social vulnerability rating (how susceptible the population is to harm) and a medium community resilience rating (its capacity to prepare for and recover from disasters). That combination — a more vulnerable population with limited resilience — can amplify the human cost of any given event.
History supports the rating: Siskiyou County has received 23 federal disaster declarations since 1964, including 7 for fire events and 6 for flood events. The most recent was Tropical Storm Hilary (hurricane), declared in November 2023.
Among 58 California counties, Siskiyou County ranks #40 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Drought | High | 73.65 / yr | $5M |
| Wildfire | High | 0.01 / yr | $14M |
| Volcanic Activity | High | 0.00 / yr | $2M |
| Landslide | Medium | 7.55 / yr | $47K |
| Riverine Flood | Medium | 1.00 / yr | $31M |
| Earthquake | Low | 0.02 / yr | $3M |
| Avalanche | Medium | 0.03 / yr | $502K |
| Heat Wave | Low | 5.86 / yr | $991K |
| Winter Weather | Medium | 29.71 / yr | $118K |
| Lightning | Low | 11.70 / yr | $98K |
| Hail | Very Low | 0.12 / yr | $51K |
| Cold Wave | Very Low | 0.01 / yr | $26K |
| Strong Wind | Very Low | 0.04 / yr | $28K |
| Tornado | Very Low | 0.04 / yr | $2K |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Ice Storm | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
Disaster History
Siskiyou County has received 23 federal disaster declarations since 1964, most recently Tropical Storm Hilary in November 2023. Most frequent causes: Fire (7), Flood (6), Severe Storm (5).
| Declared | Type | Disaster |
|---|---|---|
| November 2023 | Hurricane | Tropical Storm Hilary |
| January 2023 | Flood | Severe Winter Storms, Flooding, Landslides, and Mudslides |
| September 2022 | Fire | Mill Fire |
| June 2021 | Fire | Lava Fire |
| October 2020 | Fire | Wildfires |
| September 2020 | Fire | Slater Fire |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| July 2018 | Fire | Klamathon Fire |
| April 2017 | Flood | Severe Winter Storms, Flooding, and Mudslides |
Showing the 10 most recent of 23 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Siskiyou County?
Siskiyou County has a composite FEMA National Risk Index score of 89.0 out of 100, placing it in the Medium category and the 89th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Siskiyou County?
The three highest-rated hazards are Drought (High, $5M EAL), Wildfire (High, $14M EAL), Volcanic Activity (High, $2M EAL). These account for most of the county's expected annual losses.
How does Siskiyou County compare to other California counties?
Siskiyou County ranks #40 of 58 California counties for overall natural disaster risk, with a medium rating.
How many federally declared disasters has Siskiyou County had?
FEMA records 23 federal disaster declarations for Siskiyou County since 1964, most often 7 for fire events and 6 for flood events. The most recent was Tropical Storm Hilary, declared in November 2023.
What does Expected Annual Loss (EAL) mean?
EAL is FEMA's estimate of average annual dollar losses from natural hazards, calculated from historical event data and exposure models. Siskiyou County's $57M EAL is a statistical average, not a guarantee for any specific year or address.