Jefferson County, Missouri Natural Disaster Risk
FEMA National Risk Index assessment · MO
MediumComposite Risk Score
National percentile: 91th
Jefferson County faces medium composite natural disaster risk (NRI Risk Index score 90.5, 91th national percentile), driven primarily by strong wind and landslide exposure. Expected annual loss across all 18 hazard types is $114M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Jefferson County is medium, with a National Risk Index score of 90.5 out of 100 — placing it in the 91st 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.
Most of Jefferson County's expected losses come from strong wind (damaging straight-line winds outside of tornadoes and hurricanes) at Very High risk — $9M in expected annual loss and about 5.60 events per year; landslide (downhill movement of rock, soil, and debris on unstable slopes) at Medium risk — $224K in expected annual loss and about 2.49 events per year; and tornado (violently rotating columns of air capable of catastrophic local damage) at High risk — $16M in expected annual loss and about 0.48 events per year. Across all hazards, FEMA estimates $114M in expected annual loss for a population of 227K.
Beyond physical exposure, Jefferson County has a very low social vulnerability rating (how susceptible the population is to harm) and a high community resilience rating (its capacity to prepare for and recover from disasters). A less vulnerable population paired with strong resilience helps the community absorb and recover from events.
The county's disaster history tells the same story: Jefferson County has received 30 federal disaster declarations since 1973, including 16 for severe storm events and 7 for flood events. The most recent was Severe Storms, Straight-Line Winds, Tornadoes, and Wildfires (severe storm), declared in May 2025.
Among 115 Missouri counties, Jefferson County ranks #5 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Strong Wind | Very High | 5.60 / yr | $9M |
| Landslide | Medium | 2.49 / yr | $224K |
| Tornado | High | 0.48 / yr | $16M |
| Hail | Medium | 5.17 / yr | $3M |
| Earthquake | Medium | 0.01 / yr | $12M |
| Heat Wave | Medium | 13.21 / yr | $5M |
| Riverine Flood | Medium | 1.79 / yr | $59M |
| Lightning | High | 54.07 / yr | $2M |
| Cold Wave | Medium | 1.37 / yr | $8M |
| Winter Weather | Medium | 8.63 / yr | $339K |
| Ice Storm | Medium | 1.19 / yr | $280K |
| Wildfire | Very Low | 0.00 / yr | $72K |
| Hurricane | Very Low | 0.02 / yr | $11K |
| Drought | Very Low | 2.05 / yr | $9K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Jefferson County has received 30 federal disaster declarations since 1973, most recently Severe Storms, Straight-Line Winds, Tornadoes, and Wildfires in May 2025. Most frequent causes: Severe Storm (16), Flood (7), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| May 2025 | Severe Storm | Severe Storms, Straight-Line Winds, Tornadoes, and Wildfires |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| July 2019 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| June 2017 | Flood | Severe Storms, Tornadoes, Straight-Line Winds and Flooding |
| January 2016 | Flood | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| January 2016 | Flood | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| August 2015 | Severe Storm | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| February 2011 | Severe Storm | Severe Winter Storm |
| June 2009 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
Showing the 10 most recent of 30 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Jefferson County?
Jefferson County has a composite FEMA National Risk Index score of 90.5 out of 100, placing it in the Medium category and the 91th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Jefferson County?
The three highest-rated hazards are Strong Wind (Very High, $9M EAL), Landslide (Medium, $224K EAL), Tornado (High, $16M EAL). These account for most of the county's expected annual losses.
How does Jefferson County compare to other Missouri counties?
Jefferson County ranks #5 of 115 Missouri counties for overall natural disaster risk, with a medium rating.
How many federally declared disasters has Jefferson County had?
FEMA records 30 federal disaster declarations for Jefferson County since 1973, most often 16 for severe storm events and 7 for flood events. The most recent was Severe Storms, Straight-Line Winds, Tornadoes, and Wildfires, declared in May 2025.
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. Jefferson County's $114M EAL is a statistical average, not a guarantee for any specific year or address.