11 FEMA areas

Tornado Risk by City in Illinois

Compare 14 cities using FEMA's relative tornado scores and annualized frequency for the county-equivalent areas shown.

Highest relative score

100.0/100

Cook County

Covered cities: Chicago and Cicero

Lowest relative score in this set

84.2/100

Macon County

Covered cities: Decatur

These are relative FEMA scores for county-equivalent areas. They are not annual probabilities or property-level findings.

Illinois tornado rankings

Cities sharing a FEMA area are grouped together and receive the same score.

Rank	FEMA area and cities	Rating	Score	Annualized frequency
#1	Cook County Chicago Cicero	Very High	100.0/100	0.57 events per year
#2	DuPage County Naperville	Very High	99.5/100	0.20 events per year
#3	Will County Joliet	Very High	99.2/100	0.57 events per year
#4	Lake County Round Lake Beach Waukegan	Very High	99.1/100	0.22 events per year
#5	Kane County Aurora Elgin	Relatively High	98.8/100	0.37 events per year
#6	Winnebago County Rockford	Relatively High	97.0/100	0.39 events per year
#7	Sangamon County Springfield	Relatively High	96.6/100	0.92 events per year
#8	Champaign County Champaign	Relatively High	95.1/100	0.98 events per year
#9	Peoria County Peoria	Relatively High	94.6/100	0.62 events per year
#10	McLean County Bloomington	Relatively Moderate	90.0/100	1.29 events per year
#11	Macon County Decatur	Relatively Moderate	84.2/100	0.64 events per year

FEMA annualizes recorded qualifying tornado occurrences across the FEMA geography and source period.

Preparing for tornado

Ready.gov Tornadoes ↗

For a home or move

✓Identify the lowest-floor interior room or nearby rated shelter you can reach quickly.
✓Review how garage doors, roof connections, and exterior objects could perform in severe wind with a qualified local professional.
✓Confirm that insurance documents cover wind damage and understand the deductible before storm season.

For a household plan

✓Enable Wireless Emergency Alerts and keep a battery-powered NOAA Weather Radio available.
✓Keep shoes, flashlights, and head protection in or beside the shelter location.
✓Practice reaching the shelter with children, pets, and anyone who needs mobility assistance.

Questions about tornado risk in Illinois

Which covered Illinois cities have the highest relative tornado risk?

Chicago and Cicero use FEMA data for Cook County, which has the highest relative tornado score in this covered set at 100.0/100. Cities sharing the same FEMA area share the same score.

Which covered Illinois area has the lowest relative tornado score?

Macon County has the lowest score in this covered set at 84.2/100. This is a relative FEMA comparison, not a declaration that every property there is safe.

Are these tornado figures city-level?

No. The city links provide geographic navigation, while the scores and frequencies cover the FEMA county-equivalent areas shown in the table. Address-level conditions require local maps and property details.

Is the FEMA relative score an annual probability?

No. The relative score compares FEMA areas on a 0–100 scale. Annualized frequency appears separately with hazard-specific units.

Source: FEMA National Risk Index v1.19.0, released March 2023. Hazard data covers FEMA county-equivalent areas.

FEMA source ↗Our methodology →