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

Jefferson County Disaster Risk

Jefferson County, Wisconsin

FEMA Risk Rating

Relatively Low

National Percentile

76th

of 3,144 counties

State Rank

#18

of 72 (1 = highest risk)

Flood Risk

79th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Relatively Low

Higher than 79% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Very Low

Higher than 40% of US counties

Tornado

Tornado and severe thunderstorm risk

Moderate

Higher than 86% of US counties

Earthquake

Seismic activity and ground shaking risk

Relatively Low

Higher than 43% of US counties

Hurricane

Tropical cyclone and hurricane risk

Very Low

Higher than 14% of US counties

Risk Overview

About Natural Disaster Risk in Jefferson County, Wisconsin

Jefferson County: Above-Average U.S. Risk

Jefferson County scores 75.80 on the composite risk index, placing it in the Relatively Low category but above many national peers. The county faces elevated exposure to multiple hazard types compared to typical U.S. counties.

Higher Risk Than Most Wisconsin Counties

Jefferson County's score of 75.80 significantly exceeds Wisconsin's state average of 59.08, ranking it among the state's higher-risk counties. The county faces substantially greater natural disaster exposure than most of its neighbors.

Kenosha and La Crosse Show Even Higher Risk

Jefferson County (75.80) ranks lower than neighboring Kenosha County (84.96) and La Crosse County (80.53). However, it faces noticeably higher risk than most other south-central Wisconsin counties.

Tornadoes, Floods, and Earthquakes Loom

Jefferson County's tornado risk of 86.13 is its most severe threat, followed by flood risk at 79.48. Earthquake risk (43.42) and wildfire risk (39.92) also present meaningful concerns for residents.

Multiple Protections Required for Jefferson

Jefferson County residents should prioritize flood insurance and a comprehensive tornado safety plan, given the county's elevated risk on both fronts. Review your homeowners policy to ensure adequate wind coverage, and consider additional earthquake insurance if you own valuable property.

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
    86th percentile
  2. #2
    FloodPrepare
    79th percentile
  3. #3
    EarthquakePrepare
    43th percentile

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

Risk Advisory: Jefferson County

Risk Verdict

Jefferson County has a below-average natural disaster risk profile, scoring at the 76th percentile nationally under FEMA's National Risk Index. 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 86th percentile nationally under FEMA's National Risk Index. Flood ranks second at the 79th percentile nationally. Additional tracked hazards include earthquake (43th percentile), wildfire (40th percentile), hurricane (14th percentile).

Preparedness Context

Tornado risk is Jefferson County's top-ranked natural hazard at the 86th 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. Flood is the second hazard driver for Jefferson County at the 79th percentile nationally, meaning households should maintain awareness of both severe-weather and flood-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 16.7 points above the Wisconsin 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, WI?
Jefferson County has a FEMA National Risk Index rating of Relatively Low, placing it in the 76th 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 (86th percentile), flooding (79th percentile), earthquake (43th percentile), wildfire (40th percentile), hurricane (14th percentile). The highest-risk hazard is tornado at the 86th 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 Wisconsin average?
Jefferson County's composite risk percentile is 76th, compared to the Wisconsin state average of 59th percentile. The state's overall risk rating is Relatively Low. This means Jefferson County faces higher natural disaster risk than the typical county in Wisconsin.
Is Jefferson County at risk for tornado?
Yes, Jefferson County's tornado risk is at the 86th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Jefferson County is at the 79th 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 76th percentile is above the Wisconsin state average of 59th percentile. This elevated risk is driven by tornado exposure (86th percentile), along with flooding risk. Geographic location, terrain, climate patterns, and proximity to flood zones or fault lines all influence a county's risk profile.
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.