Jefferson County, MO

FEMA National Risk Index scores, disaster declarations & hazard data

Population: 226,703 · Cities: Arnold , Festus

Relatively Moderate Riskier than 91% of US counties
Very Low Relatively Low Relatively Moderate Relatively High Very High

Jefferson County has experienced 30 federally declared disasters since 1973, most recently Severe Storms, Straight-Line Winds, Tornadoes, And Wildfires in 2025. Its overall natural hazard risk is rated Relatively Moderate — near the middle compared to other US counties.

Jefferson County's highest-rated hazards are strong wind, landslide, and tornado, with its top risk rated "Very High" by FEMA's National Risk Index. Recorded storm events have increased 33% over the past five years compared to the prior five-year period. Community vulnerability is relatively low (11th percentile nationally), indicating stronger recovery capacity than most US counties.

Past disasters & FEMA designations

A federal disaster declaration officially designates a county for FEMA disaster assistance. Jefferson County has been designated in 30 declarations since 1973, covering 7 disaster types including severe storm (16), flood (7), biological (2).

2002–2026
Year Type Event name
2025 Severe Storm Severe Storms, Straight-Line Winds, Tornadoes, And Wildfires
2020 Biological Covid-19 Pandemic
2020 Biological Covid-19
2019 Severe Storm Severe Storms, Tornadoes, And Flooding
2017 Flood Severe Storms, Tornadoes, Straight-Line Winds And Flooding
2016 Flood Severe Storms, Tornadoes, Straight-Line Winds, And Flooding
2016 Flood Severe Storms, Tornadoes, Straight-Line Winds, And Flooding
2015 Severe Storm Severe Storms, Tornadoes, Straight-Line Winds, And Flooding
2011 Severe Storm Severe Winter Storm
2009 Severe Ice Storm Severe Winter Storm

Showing the 10 most recent of 30 total declarations since 1973.

Source: FEMA OpenFEMA Disaster Declarations Summaries. A single disaster can produce more than one record per county. Data current through September 2026.

Risk by hazard type

Hazard Risk rating Risk score Recorded events Deaths Prop. damage
Wildfire Very Low 53.1 0 0
Inland Flooding Relatively Moderate 91.4 15 1 $240K
Coastal Flooding Not Applicable 0 0
Earthquake Relatively Moderate 93.4
Heat Wave Relatively Moderate 92.1 11 0
Tornado Relatively High 95.1 10 0 $935K
Hurricane Very Low 23.7 0 0
Hail Relatively Moderate 93.9 70 0 $5K
Strong Wind Very High 98.6 0 0
Winter Weather Relatively Moderate 84.1 0 0
Ice Storm Relatively Moderate 69.4
Cold Wave Relatively Moderate 88.9
Lightning Relatively High 91.2 1 1
Drought Very Low 22.3 0 0
Landslide Relatively Moderate 95.9 0 0
Avalanche Not Applicable
Tsunami Not Applicable
Volcanic Activity Not Applicable

Scores are 0–100 percentiles relative to all US counties — higher means more exposed, not that a disaster is likely this year. Event counts: NOAA Storm Events 2016–2026; earthquake counts from USGS ComCat (M3.0+, 1996–2026). See the methodology page for details.

Community vulnerability

Jefferson County ranks in the 11th percentile (Very low) for community vulnerability — a measure of how hard disaster impacts tend to hit residents. Higher vulnerability means more displacement, worse health outcomes, and slower recovery after a disaster.

SVI theme Percentile Vulnerability level
Overall 11th Very low
Socioeconomic status 19th Very low
Household characteristics 22nd Very low
Racial & ethnic minority status 28th Low
Housing type & transportation 10th Very low

Source: CDC/ATSDR Social Vulnerability Index 2022. Percentiles compare counties nationally — higher means more vulnerable relative to other counties. See CDC SVI for full methodology.

Future risk outlook

Wildfire metric National percentile Level
Burn probability 42nd Relatively Moderate
Risk to homes 40th Relatively Moderate
Buildings in direct exposure zone 57.6%

NOAA tracked 107 weather events in this county over 2016–2025: 46 in 2016–20 vs 61 in 2021–25 (+33% — frequency increasing).

Wildfire: USDA Forest Service Wildfire Risk to Communities (RDS-2020-0016-2) — modeled values, not annual forecasts. See wildfirerisk.org. Inland flood and heat projections pending data availability; coastal sea-level projections are available for select coastal counties below — see the data page.

Nearby counties

Compare Jefferson County with other counties → All Missouri counties →

Frequently asked questions

What natural hazards pose the greatest risk in Jefferson County?

According to the FEMA National Risk Index, the highest-risk hazards in Jefferson County, Missouri are strong wind, landslide, and tornado. The county's overall natural hazard risk is rated Relatively Moderate — near the middle compared to other US counties.

Has Jefferson County received federal disaster declarations?

Yes. Jefferson County has received 30 federal disaster declarations since 1973, including declarations in 2025. The most common disaster type on record is severe storm (16 declarations).

Has Jefferson County had any FEMA disaster declarations in 2024, 2025, or 2026?

Yes. Recent federal disaster declarations for Jefferson County include Severe Storms, Straight-Line Winds, Tornadoes, And Wildfires (2025). See the declarations table above for the full history since 1973.

How does Jefferson County's natural hazard risk compare to nearby counties?

Among neighboring counties, St. Louis County, MO has the highest overall natural hazard risk (Relatively High) and Monroe County, IL has the lowest (Very Low). Jefferson County is rated Relatively Moderate overall.

How is Jefferson County's composite disaster risk index calculated?

Jefferson County's composite disaster risk index — officially FEMA's National Risk Index (NRI) — scores every US county on a 0–100 percentile scale across 18 natural hazard types, factoring in expected annual loss, social vulnerability, and community resilience. Jefferson County's composite score of 91 means its overall natural hazard risk is higher than 91% of US counties.

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