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

DeKalb County Disaster Risk

DeKalb County, Illinois

FEMA Risk Rating

Relatively Low

National Percentile

81th

of 3,144 counties

State Rank

#22

of 102 (1 = highest risk)

Flood Risk

83th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Moderate

Higher than 83% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Very Low

Higher than 6% of US counties

Tornado

Tornado and severe thunderstorm risk

Moderate

Higher than 88% of US counties

Earthquake

Seismic activity and ground shaking risk

Relatively Low

Higher than 76% of US counties

Hurricane

Tropical cyclone and hurricane risk

Very Low

Higher than 20% of US counties

Risk Overview

About Natural Disaster Risk in DeKalb County, Illinois

DeKalb faces notably elevated disaster risk

With a composite risk score of 80.82, DeKalb County rates as "Relatively Low" but sits well above the national average for natural disaster exposure. This places the county in a higher-risk category than most Illinois counties and demands serious preparedness investment.

Among Illinois's riskiest counties

DeKalb's 80.82 score ranks it in the upper tier of Illinois counties, where the state average is 54.46. Only the most hazard-prone Illinois counties exceed DeKalb's risk profile, making it a standout in terms of natural disaster exposure.

Significantly riskier than surrounding areas

DeKalb (80.82) faces roughly double the risk of nearby Crawford (37.02) and De Witt (29.26) counties. Douglas County (62.12) also sits considerably safer, revealing DeKalb as an outlier in its region for natural disaster vulnerability.

Tornadoes and floods dominate threats

DeKalb residents face the state's most severe tornado risk at 88.10, combined with exceptionally high flood exposure at 82.98. These two hazards far outpace other threats and require the most robust preparation and insurance strategies.

Invest in comprehensive disaster coverage

Flood insurance and tornado-rated wind coverage are non-negotiable for DeKalb homeowners, given the county's extreme exposure to both hazards. Dedicated tornado shelters or safe rooms should be a serious consideration, alongside detailed family emergency plans tested annually.

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

Preparedness Guide

What to Prepare for in DeKalb County

Top Hazards by Exposure

  1. #1
    TornadoPrepare
    88th percentile
  2. #2
    FloodPrepare
    83th percentile
  3. #3
    EarthquakePrepare
    76th percentile

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

Risk Advisory: DeKalb County

Risk Verdict

DeKalb County sits below the national average for natural disaster exposure, ranking at the 81th percentile across all U.S. counties. DeKalb County's elevated composite score reflects cumulative multi-hazard exposure; households should prepare for the county's two or three primary hazard types.

Hazard Breakdown

Tornado risk is DeKalb County's dominant natural hazard, ranked at the 88th percentile nationally under FEMA's National Risk Index. Flood ranks second at the 83th percentile nationally. Additional tracked hazards include earthquake (76th percentile), hurricane (20th percentile), wildfire (6th percentile).

Preparedness Context

Ranked at the 88th percentile nationally for tornado risk, DeKalb County is in a zone where storm shelters have the highest per-dollar protective value of any mitigation investment. DeKalb County's county shelter map is typically available through the local emergency management office. The secondary flood hazard at the 83th percentile nationally adds seasonal complexity to DeKalb County's preparedness calendar, since flood and tornado risk often peak at different points in the year. DeKalb County residents can check the county's emergency management website for community shelter locations nearest their address — a step worth completing now, not during a warning.

Regional Context

A composite score 26.4 points above the Illinois state average puts DeKalb County in a higher-risk category than most counties in the state.

Is your household prepared for DeKalb 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 DeKalb County, IL?
DeKalb County has a FEMA National Risk Index rating of Relatively Low, placing it in the 81th 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 DeKalb County?
DeKalb County is evaluated for five major natural hazard types: tornado (88th percentile), flooding (83th percentile), earthquake (76th percentile), hurricane (20th percentile), wildfire (6th percentile). The highest-risk hazard is tornado at the 88th 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 DeKalb County risk compare to the Illinois average?
DeKalb County's composite risk percentile is 81th, compared to the Illinois state average of 55th percentile. The state's overall risk rating is Relatively Low. This means DeKalb County faces higher natural disaster risk than the typical county in Illinois.
Is DeKalb County at risk for tornado?
Yes, DeKalb County's tornado risk is at the 88th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, DeKalb County is at the 83th 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 DeKalb County higher risk than average?
DeKalb County's composite risk score of 81th percentile is above the Illinois state average of 55th percentile. This elevated risk is driven by tornado exposure (88th percentile), along with flooding and earthquake 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.