riskbycounty
FEMA NRI v1.20Released December 2025Methodology

St. Clair County Disaster Risk

St. Clair County, Illinois

FEMA Risk Rating

Relatively High

NRI score (0–100 relative scale)

94.9

FEMA composite county value

State Rank

#5

of 102, sorted high to low by RiskByCounty

Flood NRI score

94.5

higher coastal/inland value

Hazard Risk Breakdown

Five selected hazard categories out of FEMA's 18. Values are FEMA NRI v1.20 scores on a 0–100 relative scale.

Earthquake

98.0 / 100

Tornado

95.5 / 100

Flood

94.5 / 100

Higher of FEMA Coastal Flooding (Not available) and Inland Flooding (94.5) NRI scores.

Hurricane

34.9 / 100

Wildfire

15.1 / 100

FEMA NRI data summary

Selected hazard scores for St. Clair County

Among the five hazard categories displayed by RiskByCounty, earthquake has the highest NRI score for this county.

Earthquake
98.0
Tornado
95.5
Flood
94.5
Hurricane
34.9
Wildfire
15.1

Higher of FEMA Coastal Flooding and Inland Flooding NRI scores

Displayed flood score
94.5
Coastal Flooding
Not available
Inland Flooding
94.5

These five categories are a selected subset of FEMA's 18 natural hazards. FEMA's composite score and official rating are separate fields in the National Risk Index dataset.

FEMA National Risk Index documentation

Official Ready.gov resource

Continue to Ready.gov for federal emergency-planning information maintained outside RiskByCounty.

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Frequently Asked Questions

How many Illinois county records are included?
RiskByCounty includes 102 Illinois county records from FEMA NRI v1.20 (December 2025).
Which FEMA county ratings appear in Illinois?
FEMA NRI v1.20 (December 2025) county rating counts for Illinois: Very Low: 37; Relatively Low: 45; Relatively Moderate: 14; Relatively High: 5; Very High: 1; Not available: 0.
How complete are the five selected hazard fields for Illinois?
FEMA NRI v1.20 (December 2025) availability among 102 county records: Flood: 102 of 102; Wildfire: 102 of 102; Tornado: 102 of 102; Earthquake: 102 of 102; Hurricane: 102 of 102. RiskByCounty displays five selected hazard categories out of FEMA's 18.
What FEMA NRI information is available for St. Clair County, IL?
St. Clair County has an official FEMA NRI v1.20 composite rating of Relatively High and an NRI score (0–100 relative scale) of 94.9. RiskByCounty ranks it 5th of 102 Illinois county records when sorting the FEMA composite NRI scores from high to low.
Which selected hazard scores are shown for St. Clair County?
RiskByCounty displays five selected hazard categories out of FEMA's 18 using FEMA NRI v1.20 (December 2025). For St. Clair County, Earthquake: 98.0; Tornado: 95.5; Flood: 94.5; Hurricane: 34.9; Wildfire: 15.1.
How is flood displayed for St. Clair County?
RiskByCounty's flood display is the higher of FEMA Coastal Flooding and Inland Flooding NRI scores. For St. Clair County, Coastal Flooding is Not available, Inland Flooding is 94.5, and the displayed flood score is 94.5.

Counties with Similar Risk

Kane County

Illinois

-0.3

Relatively High

NRI score 94.6

Lake County

Illinois

+1.1

Relatively High

NRI score 96.0

Madison County

Illinois

-1.5

Relatively Moderate

NRI score 93.4

Published by RiskByCounty

County summaries are deterministic transformations of frozen FEMA county fields. No external subject-matter reviewer is credited.

Published · Updated

Data Source

County data sourced from FEMA National Risk Index v1.20, released December 2025. Values are labeled NRI score (0–100 relative scale). RiskByCounty displays five selected hazard categories out of FEMA's 18; flood is the higher of the Coastal Flooding and Inland Flooding source scores.

RiskByCounty presents county-level source fields and deterministic arithmetic summaries.

Explore more data for St. Clair County

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