riskbycounty
FEMA NRI 1.19.0Updated Nov 2023 · Coverage 2014–2023Methodology

Jefferson County Disaster Risk

Jefferson County, Missouri

FEMA Risk Rating

Relatively Moderate

National Percentile

91th

of 3,144 counties

State Rank

#5

of 115 (1 = highest risk)

Flood Risk

91th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Moderate

Higher than 91% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Relatively Low

Higher than 53% of US counties

Tornado

Tornado and severe thunderstorm risk

Relatively High

Higher than 95% of US counties

Earthquake

Seismic activity and ground shaking risk

Moderate

Higher than 93% of US counties

Hurricane

Tropical cyclone and hurricane risk

Very Low

Higher than 24% of US counties

Risk Overview

About Natural Disaster Risk in Jefferson County, Missouri

Jefferson faces above-average U.S. risk

Jefferson County's composite risk score of 90.52 places it in the upper tier nationally, with a Relatively Moderate rating. This score reflects exposure to multiple significant hazards that exceed typical American county risk profiles.

Missouri's highest-risk county

Jefferson County leads Missouri with a composite score of 90.52, nearly 40 points above the state average of 50.56. The county faces the state's most concentrated natural disaster exposure.

Substantially riskier than peers

Jefferson's 90.52 score far exceeds neighboring Johnson County (54.93) and Lafayette County (52.51). The county's risk level is notably higher than most other areas in central Missouri.

Earthquakes, floods, and tornadoes converge

Jefferson experiences high earthquake risk (93.42), flood risk (91.38), and tornado risk (95.10)—among Missouri's highest levels across all three hazards. This triple threat makes it one of the state's most hazard-exposed counties.

Layer multiple insurance protections

Jefferson homeowners must secure flood insurance and verify tornado coverage immediately, given the county's extreme exposure to both hazards. Consider earthquake insurance as well; ask your agent about bundle discounts for comprehensive multi-hazard protection.

Source: FEMA National Risk Index · Narrative reviewed by Evan Brooks, Data Editor

Preparedness Guide

What to Prepare for in Jefferson County

Top Hazards by Exposure

  1. #1
    TornadoPrepare
    95th percentile
  2. #2
    EarthquakePrepare
    93th percentile
  3. #3
    FloodPrepare
    91th percentile

Source: FEMA National Risk Index v1.19.0 · Percentiles are national (3,144 counties)

Local Resources

Risk Advisory: Jefferson County

Risk Verdict

Jefferson County faces a moderate natural disaster risk profile, ranking at the 91th percentile nationally under FEMA's composite risk model. This risk level calls for more than general awareness: insurance coverage review, a family communication plan, and a prepared go-bag are practical priorities.

Hazard Breakdown

Tornado risk is Jefferson County's dominant natural hazard, ranked at the 95th percentile nationally under FEMA's National Risk Index. Earthquake ranks second at the 93th percentile nationally. Additional tracked hazards include flood (91th percentile), wildfire (53th percentile), hurricane (24th percentile).

Preparedness Context

Tornado risk is Jefferson County's top-ranked natural hazard at the 95th percentile nationally. For Jefferson County households, the most protective action available is identifying a reinforced interior room on the lowest floor — a bathroom, closet, or central hallway away from windows. Earthquake is the second hazard driver for Jefferson County at the 93th percentile nationally, meaning households should maintain awareness of both severe-weather and earthquake-specific warning systems. A battery-powered NOAA All Hazards weather radio with an auto-alert tone is the highest-leverage single item for tornado preparedness in Jefferson County, since it delivers warnings even when power is out and phone networks are congested.

Regional Context

Jefferson County's composite risk score sits 40.0 points above the Missouri county average, placing it among the more hazard-exposed counties in the state.

Is your household prepared for Jefferson County's hazards?

Review FEMA's county-specific preparedness checklists and emergency planning guides.

FEMA Ready Guide →

Frequently Asked Questions

What is the natural disaster risk in Jefferson County, MO?
Jefferson County has a FEMA National Risk Index rating of Relatively Moderate, placing it in the 91th percentile nationally out of 3,144 counties. This composite score reflects the county's overall exposure to natural hazards including floods, wildfires, tornadoes, earthquakes, and hurricanes, weighted by expected annual loss and social vulnerability.
What types of natural hazards affect Jefferson County?
Jefferson County is evaluated for five major natural hazard types: tornado (95th percentile), earthquake (93th percentile), flooding (91th percentile), wildfire (53th percentile), hurricane (24th percentile). The highest-risk hazard is tornado at the 95th percentile nationally. These scores are derived from FEMA's National Risk Index, which analyzes expected annual loss, social vulnerability, and community resilience for each hazard type.
How does Jefferson County risk compare to the Missouri average?
Jefferson County's composite risk percentile is 91th, compared to the Missouri state average of 51th percentile. The state's overall risk rating is Relatively Low. This means Jefferson County faces higher natural disaster risk than the typical county in Missouri.
Is Jefferson County at risk for tornado?
Yes, Jefferson County's tornado risk is at the 95th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Jefferson County is at the 91th percentile.
How is natural disaster risk measured?
FEMA's National Risk Index (NRI) calculates risk scores for 18 natural hazard types across all U.S. counties and census tracts. The composite score combines Expected Annual Loss (estimated dollar losses from each hazard), Social Vulnerability (demographic factors affecting disaster impact), and Community Resilience (ability to recover). Percentile scores rank each county against all 3,144 U.S. counties, and risk ratings range from Very Low to Very High.
Why is Jefferson County higher risk than average?
Jefferson County's composite risk score of 91th percentile is above the Missouri state average of 51th percentile. This elevated risk is driven by tornado exposure (95th percentile), along with earthquake and flooding and wildfire risk. Geographic location, terrain, climate patterns, and proximity to flood zones or fault lines all influence a county's risk profile.

Counties with Similar Risk

Greene County

Missouri

-0.4

Relatively Moderate

90th percentile

Clay County

Missouri

-0.7

Relatively Moderate

90th percentile

St. Charles County

Missouri

+2.1

Relatively Moderate

93th percentile

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor

Data Source

Risk data sourced from the FEMA National Risk Index (NRI). Risk scores are relative rankings (0–100) across all US counties — not absolute risk measures. Higher scores indicate higher relative risk compared to other counties.

Disclaimer: This data is informational only. It is not financial, insurance, or legal advice. Always consult a qualified professional before making insurance or real estate decisions.

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