Tornado and Severe Weather Climatology for Northern Illinois and Northwest Indiana

Statistics

NWS Chicago CWA Tornado Counts by EF (Enhanced Fujita) Scale 1950-2017
Maximum EF Damage	Count	Mean Length (mi)	Mean Width (yds)	Fatalities	Injuries
EF-0	227	1.14	43.4	0	7
EF-1	236	3.20	88.6	2	53
EF-2	113	7.13	147.9	10	469
EF-3	27	18.8	360.1	14	140
EF-4	11	28.62	681.8	90	1,660
EF-5	1	16.40	600.0	29	350
All Tornadoes	615	4.32	106.2	145	2,679

Significant (EF-2+)	152	10.81	227.2	143	2,619
Violent (EF-4+)	12	27.60	675.0	119	2,010

For more on the Enhanced Fujita Scale for tornado damage, visit here.

NWS Chicago CWA Tornado Percentage Counts by Magnitude 1950-2017

EF Damage	% of All Tornadoes
EF-0	36.9%
EF-1	38.4%
EF-2	18.4%
EF-3	4.4%
EF-4	1.8%
EF-5	0.2%

Significant (EF-2+)	24.8%
Violent (EF-4+)	2.0%

Spatial Data

Tornado Paths Across the U.S. From 1950 - Present

Temporal Data

Same Data as Above but for 1995-Present

Tornadoes by Time of Day in the Cool Season

For the entire state of Illinois, see these graphics: Time of Year | Time of Day

For the entire U.S., see these graphics: Time of Year | Time of Day

Year-To-Year Charts

NWS Chicago CWA Annual Tornadoes & Significant Tornadoes

NWS Chicago CWA Annual Tornado Fatalities

1950 to 2014

Fatalities by Year in the NWS Chicago CWA

For tornado trends across the United States, visit here, and for significant tornado trends, see here.

County Scale

For listings of the total number of tornadoes in Illinois by county from 1950-2019, see here. For the same but normalized by county area, see here. These numbers are courtesy of NWS Central Illinois.

These maps are courtesy of the NOAA Midwestern Regional Climate Center (MRCC). An interactive tornado map from the MRCC is available here. Please note that these maps are created by the documented beginning and end points of the tornadoes. These plotted paths do not take into account the exact tornado tracks that often have subtle deviations. Thus these plotted paths are always straight lines. While these are really sound approximations of the historical tornado paths, they should not be considered exactly precise.

Illinois