Illinois State Water Survey - University of Illinois at Urbana-Champaign

Tornadoes in Illinois

Dr. Jim Angel, State Climatologist

Tornadoes have captured the imagination of the public like no other weather phenomena. Illinois is ranked high in terms of the number of tornadoes and tornado impacts (damages, deaths, and injuries). In fact, Illinois has experienced some of the worst tornadoes in U.S. history. The infamous Tri-State tornado occurred on March 18, 1925, passing through southern Missouri, Illinois, and Indiana, leaving 695 dead and 2000 injured. The Mattoon tornado of May 26, 1917, left 101 dead and 638 injured.

On a brighter note, the first documented case of a tornado being detected by radar occurred in Illinois. On April 9, 1953, staff at the Illinois State Water Survey tracked the development, growth, and movement of a tornado, as identified by the distinctive " hook echo". This discovery led to the development of a nationwide network of radar sites in the 1950s to spot and track tornadoes.

New and improved

• tornado maps for Illinois and for each county for the period 1950-2010.
• tornado graphs for Illinois for the period 1950-2010.

This page provides a tornado climatology for Illinois. Items to check out are:

• The record setting 2006 tornado season
• NWS account of the March 18, 1925 Tri-State Tornado
• NWS account of the May 26, 1917, Mattoon Tornado
• NWS study of significant Chicago-area tornadoes

Table 1. Illinois tornado events, deaths, and injuries since 1981.

Year	Number of Events	Deaths	Injuries
2012	39	8	111
2011	76	0	8
2010	52	1	40
2009	59	0	27
2008	47	0	11
2007	23	0	3
2006	124**	1	49
2005	19	0	0
2004	80	9	23
2003	120	2	82
2002	35	4	64
2001	21	0	3
2000	55	0	8
1999	64	3	29
1998	99	0	27
1997	29	0	3
1996	62	1	80
1995	76	0	80
1994	20	0	0
1993	34	0	0
1992	23	0	2
1991	32	0	23
1990	50	30	365
1989	15	0	56
1988	20	0	6
1987	22	0	2
1986	22	0	12
1985	15	1	11
1984	34	1	20
1983	14	2	43
1982	35	13	287
1981	33	1	48
1980	14	0	7

**new record for Illinois

Other Resources

Water Survey Resources

Here are Water Survey-related reports on Illinois tornadoes. They are available as PDF files.

• Angel, J.R., 2002:Temporal Aspects of Illinois Tornadoes: 1950-1998, Vol. 95, #3, pp. 163-174, Transactions of the Illinois Academy of Science.
• Wendland and Hoffman, 1993:Illinois Tornadoes Prior to 1916, Vol 86, pp. 1-10, Transactions of the Illinois Academy of Science.
• Wendland and Guinan, 1988:A Tornado and Severe Windstorm Climatology for Illinois: 1955-1986, Vol. 81, pp. 131-146, Transactions of the Illinois Academy of Science.
• Wilson and Changnon, 1971:Illinois Tornadoes, Circular 103, Illinois State Water Survey.

Outside Resources

• NOAA Storm Prediction Center: Tornado FAQ | Interesting Statistics
• NWS, Lincoln IL -
  • Illinois Severe Weather Facts (pdf)
  • Central Illinois Tornado Climatology
• NWS, Chicago IL - Significant Chicago Tornadoes
• FEMA - Tornado Information
• NCDC - Individual Events
• NCAR - Extreme Weather Sourcebook
• Tom Grazulis The Tornado Project

Fujita Tornado Scale

Tornadoes were typically classified using the Fujita or F-scale, the higher the number the worse the damage. In recent years, the F-scale was changed to the EF-scale or "Enhanced Fujita"-scale. This was based on refinements to the original scale and is described in more detail by the NWS here and here. Below is the original scale.

Table 2. Original Fujita Tornado Scale

Scale	Wind Speeds	Typical Damage
F-0	40-72 mph	Light damage: some damage to chimneys; tree branches broken; sign boards damaged.
F-1	73-112 mph	Moderate damage: peels off some roofing; mobile homes pushed off foundation; moving cars blown off road.
F-2	113-157 mph	Considerable damage: roofs torn off houses; mobile home demolished; large trees snapped or uprooted; cars lifted off ground.
F-3	158-205 mph	Severe damage: roofs and walls blown down; trains overturned; most trees uprooted; cars lifted and tossed.
F-4	207-260 mph	Devastating damage: well-constructed buildings leveled; cars tossed some distance;
F-5	261-318 mph	Incredible damage: massive destruction; car-size objects thrown as far as 100 meters; most buildings leveled and swept away; incredible phenomena will occur.