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

Mason County Disaster Risk

Mason County, Illinois

FEMA Risk Rating

Relatively Low

National Percentile

43th

of 3,144 counties

State Rank

#65

of 102 (1 = highest risk)

Flood Risk

47th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Relatively Low

Higher than 47% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Very Low

Higher than 2% of US counties

Tornado

Tornado and severe thunderstorm risk

Relatively Low

Higher than 52% of US counties

Earthquake

Seismic activity and ground shaking risk

Relatively Low

Higher than 64% of US counties

Hurricane

Tropical cyclone and hurricane risk

Very Low

Higher than 23% of US counties

Risk Overview

About Natural Disaster Risk in Mason County, Illinois

Mason County's risk sits below average

Mason County's composite risk score of 43.03 places it in the Relatively Low category, below Illinois's state average of 54.46. This indicates manageable natural disaster risk for most residents.

Lower-risk county in Illinois

Mason County ranks in the safer half of Illinois counties, with exceptionally low wildfire risk (1.62) and flood risk (47.20). Earthquake exposure of 63.77 is moderate, while tornado risk of 52.07 remains below state averages.

Among the safer central Illinois counties

Mason County's score of 43.03 is comparable to nearby McDonough County (37.53) and substantially safer than Marshall County's 27.23. It remains far safer than the higher-risk counties of southwestern Illinois.

Flooding poses the most significant threat

Mason County's flood risk of 47.20 represents its greatest vulnerability, though still below the state average. Tornado and earthquake risks are moderate, with scores of 52.07 and 63.77 respectively.

Focus on flood insurance coverage

Mason County residents should prioritize flood insurance, especially those near rivers or low-lying areas, as standard policies exclude water damage. A basic homeowners policy combined with flood coverage provides solid protection for most Mason County properties.

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

Preparedness Guide

What to Prepare for in Mason County

Top Hazards by Exposure

  1. #1
    EarthquakePrepare
    64th percentile
  2. #2
    TornadoPrepare
    52th percentile
  3. #3
    FloodPrepare
    47th percentile

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

Risk Advisory: Mason County

Risk Verdict

Natural hazard pressure in Mason County is below the national midpoint, with a composite score at the 43th percentile. A 43th percentile score positions Mason County among the nation's lower-risk counties, a genuinely favorable outcome — one that simple, low-cost preparedness habits can reinforce further.

Hazard Breakdown

Earthquake risk is Mason County's dominant natural hazard, ranked at the 64th percentile nationally under FEMA's National Risk Index. Tornado ranks second at the 52th percentile nationally. Additional tracked hazards include flood (47th percentile), hurricane (23th percentile), wildfire (2th percentile).

Preparedness Context

Earthquake exposure at the 64th percentile nationally puts Mason County in a zone where utilities — gas, water, electrical — are the most common post-quake hazard. Knowing how to shut off the main gas valve is an important household skill to develop before an event occurs. The county's tornado risk at the 52th percentile nationally is a seasonal consideration alongside the year-round earthquake threat, requiring awareness of both hazard types. Mason County households benefit from keeping shoes and a flashlight near the bed — post-earthquake navigation through debris in the dark is a common cause of secondary injury. This low-cost step has outsized protective value.

Regional Context

Mason County's composite risk score sits 11.4 points below the Illinois county average, reflecting a more favorable hazard environment than the state typical.

Is your household prepared for Mason 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 Mason County, IL?
Mason County has a FEMA National Risk Index rating of Relatively Low, placing it in the 43th 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 Mason County?
Mason County is evaluated for five major natural hazard types: earthquake (64th percentile), tornado (52th percentile), flooding (47th percentile), hurricane (23th percentile), wildfire (2th percentile). The highest-risk hazard is earthquake at the 64th 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 Mason County risk compare to the Illinois average?
Mason County's composite risk percentile is 43th, compared to the Illinois state average of 55th percentile. The state's overall risk rating is Relatively Low. This means Mason County faces lower natural disaster risk than the typical county in Illinois.
Is Mason County at risk for earthquake?
Yes, Mason County's earthquake risk is at the 64th percentile nationally. This is above the national median. For flooding specifically, Mason County is at the 47th 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.
Is Mason County a safe place to live?
Mason County's composite risk score of 43th percentile is below the Illinois state average of 55th percentile, indicating relatively lower exposure to natural hazards. However, no county is completely risk-free. The primary hazard type is earthquake at the 64th percentile. Residents should still maintain emergency preparedness plans and appropriate insurance coverage.
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.