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Cook County, Illinois severe weather history spans 2,633 recorded events between 1954 and 2026. The dominant hazard is thunderstorm wind, accounting for 52.6% of all recorded events. It ranks #5 nationally and #1 in Illinois.
2,633
Recorded events
57
Direct deaths
886
Direct injuries
$1.7B
Property damage
The record
What the Cook County, Illinois severe weather history record shows
Across the archive, Cook County, Illinois severe weather history averages 36.6 recorded events a year. The busiest stretch on record is the 2020s, with 943 events logged in that decade alone. Roughly 289 events fall before 1990 and 2,344 from 1990 onward — a gap that reflects the expansion of NOAA reporting practice as much as the weather itself.
The deadliest hazard in the Cook County, Illinois record is tornado, responsible for 39 direct deaths. The costliest is flash flood, with $1.5B in reported property damage. In total, 8 distinct hazard types appear in this county archive, each listed with its own dated record below.
By hazard type
Every hazard type recorded in Cook County
| Hazard | Events | Deaths | Damage | Max | Span |
|---|---|---|---|---|---|
| Thunderstorm Wind | 1,384 | 11 | $17.2M | 130 | 1955–2026 |
| Hail | 639 | 0 | $18.8M | 2.75 | 1955–2026 |
| Flood | 209 | 2 | $7.2M | 0 | 1998–2026 |
| Flash Flood | 191 | 1 | $1.5B | 0 | 1996–2026 |
| Tornado | 85 | 39 | $118.3M | F4 | 1954–2025 |
| Heavy Rain | 61 | 1 | $330K | 0 | 2003–2025 |
| Lightning | 57 | 3 | $6.5M | 0 | 1996–2025 |
| Funnel Cloud | 7 | 0 | $0 | 0 | 2001–2022 |
Decade by decade
Cook County, Illinois severe weather history by decade
Reporting practice changed over time — early decades are undercounted, not calmer.
Tornado tracks
Paths crossing this county
87 mapped tornado paths intersect this county: 73 touched down inside it and 14 crossed in from a neighbouring county. This comes from path geometry, not county-tagged reports.
| Date | Scale | Deaths | Injuries | Path length | Origin |
|---|---|---|---|---|---|
| 1967-04-21 | EF4 | 33 | 500 | 15.0 mi | Touched down here |
| 1976-06-13 | EF4 | 2 | 23 | 3.3 mi | Touched down here |
| 2021-06-20 | EF3 | 0 | 11 | 17.6 mi | Crossed in |
| 1991-03-27 | EF3 | 0 | 7 | 15.0 mi | Crossed in |
| 1976-03-12 | EF2 | 2 | 66 | 15.1 mi | Touched down here |
| 1965-11-12 | EF2 | 2 | 90 | 35.9 mi | Crossed in |
| 1966-06-09 | EF2 | 1 | 30 | 2.5 mi | Touched down here |
| 1961-03-04 | EF2 | 1 | 115 | 7.9 mi | Touched down here |
| 2024-07-15 | EF2 | 0 | 2 | 34.6 mi | Crossed in |
| 2008-06-07 | EF2 | 0 | 6 | 6.5 mi | Crossed in |
Significant events
Deadliest events on record in Cook County
| Date | Type | Location | Deaths | Injuries | Damage |
|---|---|---|---|---|---|
| Apr 21, 1967 | Tornado | 33 | 500 | $25.0M | |
| Mar 12, 1976 | Tornado | 2 | 41 | $2.5M | |
| Jun 13, 1976 | Tornado | 2 | 23 | $2.5M | |
| May 5, 1991 | Thunderstorm Wind | 2 | 2 | $0 | |
| Mar 4, 1961 | Tornado | 1 | 115 | $25.0M | |
| Jun 9, 1966 | Tornado | 1 | 30 | $0 | |
| Oct 13, 2001 | Thunderstorm Wind | NILES | 1 | 6 | $5K |
| Jun 29, 1990 | Thunderstorm Wind | 1 | 6 | $0 |
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
A line of thunderstorms moved east across the City of Chicago producing winds in excess of 60 mph. The City of Chicago Department of Streets and Sanitation received thousdands of reports of trees and limbs blown down, and light poles blown down across the city. The worst of the storm of the damage occurred on the south side of the city. A man and a woman were injured by falling tree limbs on the south side of Chicago. A 21 year old woman was struck by a falling tree limb in the Beverly area. She was in the hospital for five weeks before succumbing to her injuries on July 23rd.
After heavy rain and flash flooding across much of southern Cook County from the early morning through the afternoon of September 13th, flooding continued across many locations through the evening hours and into the early morning hours of September 14th, when another wave of heavy rain moved across the area. A elderly man fell head first into a flooded window well and drowned in Oak Lawn. He was trying to clear a plugged drain in the window well.
Thunderstorms training over the Chicago metro area dropped from around 1.5 inches to just over three inches of rain in just a couple hours. A construction worker inside the sewer in the 3000 block of North Rockwell Street was swept away by rushing water after removing his harness to reach a confined space about 30 inches in diameter.
Context
Risk, population and federal disasters
Very High
FEMA NRI risk rating
5,182,090
Population (ACS)
$325K
Median home value
24
Federal declarations
| Declared | Incident | Title | Type |
|---|---|---|---|
| Sep 20, 2024 | Flood | SEVERE STORMS, TORNADOES, STRAIGHT-LINE WINDS, AND FLOODNG | DR |
| Nov 20, 2023 | Flood | SEVERE STORMS AND FLOODING | DR |
| Aug 15, 2023 | Severe Storm | SEVERE STORMS AND FLOODING | DR |
| Mar 26, 2020 | Biological | COVID-19 PANDEMIC | DR |
| Mar 13, 2020 | Biological | COVID-19 | EM |
| May 10, 2013 | Flood | SEVERE STORMS, STRAIGHT-LINE WINDS, AND FLOODING | DR |
Within the county
Most affected places
- Chicago 106
Quick answers
Frequently asked
How many severe weather events have been recorded in Cook County, Illinois?
2,633 events are on record between 1954 and 2026, causing 57 direct deaths and $1.7B in property damage.
What is the most common severe weather hazard in Cook County?
Thunderstorm Wind, with 1,384 recorded events — 52.6% of everything in the archive for this county.
How many tornadoes have crossed Cook County?
87 mapped tornado paths intersect the county boundary; 73 of them touched down inside it. This is derived from path geometry, not county-tagged reports.
How many federal disaster declarations cover Cook County?
24 federal disaster declarations from FEMA include Cook County, each tied to a specific incident period.
How risky is Cook County compared with the rest of the country?
FEMA's National Risk Index rates Cook County as very high risk, placing it in the 100 percentile of its state for expected annual loss.
Where does the Cook County, Illinois severe weather history data come from?
Every figure is drawn from United States federal public-domain records: NOAA/NCEI Storm Events for the event archive, NOAA SPC SVRGIS for mapped tornado paths, FEMA for disaster declarations and risk ratings, and the U.S. Census for population context. Dates are shown in UTC and recent entries may still be revised by NOAA.
Nearby
Neighbouring counties
- Coles County 418
- Crawford County 281
- Clinton County 354
- Cumberland County 180
- Clay County 364
- DeKalb County 485
Cite this page
“Cook County, Illinois.” Severe Weather History. severeweatherhistory.com/county/illinois/cook-county/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.