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

LaSalle County Disaster Risk

LaSalle County, Illinois

FEMA Risk Rating

Relatively Moderate

National Percentile

86th

of 3,144 counties

State Rank

#16

of 102 (1 = highest risk)

Flood Risk

88th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Moderate

Higher than 88% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Very Low

Higher than 21% of US counties

Tornado

Tornado and severe thunderstorm risk

Moderate

Higher than 84% of US counties

Earthquake

Seismic activity and ground shaking risk

Moderate

Higher than 82% of US counties

Hurricane

Tropical cyclone and hurricane risk

Very Low

Higher than 30% of US counties

Risk Overview

About Natural Disaster Risk in LaSalle County, Illinois

LaSalle County faces moderate-to-high risk nationally

With a composite risk score of 86.1 and a relatively moderate rating, LaSalle County's disaster exposure exceeds the national average. This score reflects meaningful vulnerability to flooding, tornadoes, and earthquakes that warrants proactive preparation.

Above average risk for Illinois

LaSalle County's score of 86.1 ranks it well above Illinois' state average of 54.5. The county is among the more hazard-prone areas in Illinois, though not in the highest tier of risk.

Riskier than some surrounding counties

LaSalle County's composite risk of 86.1 exceeds neighboring Livingston County (71.8) and Lee County (54.4). Its elevated flood risk of 88.2 and tornado risk of 84.1 position it as one of the more vulnerable counties in the region.

Flooding and tornadoes drive your risk

Flood risk of 88.2 and tornado risk of 84.1 are LaSalle County's primary hazard concerns. Both hazards have the potential to cause significant property damage and warrant serious mitigation planning.

Prioritize flood and wind protection

LaSalle County homeowners should ensure flood insurance is in place through the NFIP or a private carrier, as standard policies don't cover flood damage. Additionally, verify that your homeowners policy includes adequate coverage for wind and hail damage from severe thunderstorms and tornadoes.

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

Preparedness Guide

What to Prepare for in LaSalle County

Top Hazards by Exposure

  1. #1
    FloodPrepare
    88th percentile
  2. #2
    TornadoPrepare
    84th percentile
  3. #3
    EarthquakePrepare
    82th percentile

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

Risk Advisory: LaSalle County

Risk Verdict

LaSalle County registers a moderately elevated natural disaster risk, ranking at the 86th percentile across all U.S. counties. High composite risk signals that multiple hazard types are elevated simultaneously; planning for more than one scenario is important in LaSalle County.

Hazard Breakdown

Flood risk is LaSalle County's dominant natural hazard, ranked at the 88th percentile nationally under FEMA's National Risk Index. Tornado ranks second at the 84th percentile nationally. Additional tracked hazards include earthquake (82th percentile), hurricane (30th percentile), wildfire (21th percentile).

Preparedness Context

LaSalle County's dominant hazard is flooding, ranked at the 88th percentile nationally. In addition to flood insurance, residents should identify their nearest evacuation shelter and store key documents in waterproof containers. Secondary tornado exposure at the 84th percentile adds a second preparedness layer; households should review coverage options and alert sign-up for both hazard types. LaSalle County's county emergency management office publishes hazard-specific guidance tailored to local conditions; bookmarking that resource and the county's alert system is a practical first step for any household.

Regional Context

LaSalle County falls 31.6 points above Illinois's typical county risk level, which means the hazard environment here is notably more demanding than the state baseline.

Is your household prepared for LaSalle 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 LaSalle County, IL?
LaSalle County has a FEMA National Risk Index rating of Relatively Moderate, placing it in the 86th 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 LaSalle County?
LaSalle County is evaluated for five major natural hazard types: flooding (88th percentile), tornado (84th percentile), earthquake (82th percentile), hurricane (30th percentile), wildfire (21th percentile). The highest-risk hazard is flooding 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 LaSalle County risk compare to the Illinois average?
LaSalle County's composite risk percentile is 86th, compared to the Illinois state average of 55th percentile. The state's overall risk rating is Relatively Low. This means LaSalle County faces higher natural disaster risk than the typical county in Illinois.
Is LaSalle County at risk for flooding?
Yes, LaSalle County's flooding risk is at the 88th percentile nationally. This places it in the top quartile for this hazard type.
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 LaSalle County higher risk than average?
LaSalle County's composite risk score of 86th percentile is above the Illinois state average of 55th percentile. This elevated risk is driven by flooding exposure (88th percentile), along with tornado 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.