Live
Active alerts for this county
Heat Advisory
Ogle; Lee; De Kalb; La Salle; Kendall; Grundy; Kankakee; Livingston; Iroquois; Ford; Northern Will; Southern Will; Eastern Will; Lake; Porter; Newton; Jasper; Benton
DeKalb County, Illinois severe weather history spans 485 recorded events between 1957 and 2026. The dominant hazard is thunderstorm wind, accounting for 64.7% of all recorded events. It ranks #928 nationally and #31 in Illinois.
485
Recorded events
2
Direct deaths
31
Direct injuries
$15.6M
Property damage
The record
What the DeKalb County, Illinois severe weather history record shows
Across the archive, DeKalb County, Illinois severe weather history averages 7.0 recorded events a year. The busiest stretch on record is the 2020s, with 157 events logged in that decade alone. Roughly 48 events fall before 1990 and 437 from 1990 onward — a gap that reflects the expansion of NOAA reporting practice as much as the weather itself.
The deadliest hazard in the DeKalb County, Illinois record is tornado, responsible for 2 direct deaths. The costliest is tornado, with $8.4M 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 DeKalb County
| Hazard | Events | Deaths | Damage | Max | Span |
|---|---|---|---|---|---|
| Thunderstorm Wind | 314 | 0 | $1.3M | 87 | 1957–2026 |
| Hail | 88 | 0 | $0 | 2.75 | 1970–2026 |
| Tornado | 28 | 2 | $8.4M | F2 | 1959–2024 |
| Flash Flood | 27 | 0 | $4.9M | 0 | 1996–2025 |
| Flood | 15 | 0 | $1.0M | 0 | 1998–2024 |
| Heavy Rain | 5 | 0 | $0 | 0 | 2009–2021 |
| Lightning | 4 | 0 | $30K | 0 | 2001–2018 |
| Funnel Cloud | 4 | 0 | $0 | 0 | 2000–2021 |
Decade by decade
DeKalb County, Illinois severe weather history by decade
Reporting practice changed over time — early decades are undercounted, not calmer.
Tornado tracks
Paths crossing this county
31 mapped tornado paths intersect this county: 25 touched down inside it and 6 crossed in from a neighbouring county. This comes from path geometry, not county-tagged reports.
| Date | Scale | Deaths | Injuries | Path length | Origin |
|---|---|---|---|---|---|
| 2015-04-09 | EF4 | 2 | 11 | 30.1 mi | Crossed in |
| 1975-06-18 | EF2 | 0 | 1 | 4.7 mi | Touched down here |
| 1958-08-15 | EF2 | 0 | 0 | 74.5 mi | Crossed in |
| 2021-08-09 | EF1 | 0 | 0 | 1.8 mi | Touched down here |
| 2021-08-09 | EF1 | 0 | 0 | 1.5 mi | Touched down here |
| 2015-04-09 | EF1 | 0 | 0 | 4.0 mi | Touched down here |
| 2013-06-12 | EF1 | 0 | 0 | 2.3 mi | Touched down here |
| 1991-04-29 | EF1 | 0 | 0 | 10.0 mi | Crossed in |
| 1967-04-21 | EF1 | 0 | 0 | 2.0 mi | Touched down here |
| 1961-09-30 | EF1 | 0 | 0 | 2.3 mi | Crossed in |
Significant events
Deadliest events on record in DeKalb County
| Date | Type | Location | Deaths | Injuries | Damage |
|---|---|---|---|---|---|
| Apr 10, 2015 | Tornado | FAIRDALE | 2 | 11 | $8.0M |
| Aug 24, 1998 | Thunderstorm Wind | KIRKLAND | 0 | 12 | $0 |
| Sep 13, 2008 | Flood | NEW LEBANON | 0 | 3 | $15K |
| Jul 27, 2003 | Thunderstorm Wind | SANDWICH | 0 | 2 | $0 |
| Jun 1, 2007 | Thunderstorm Wind | SANDWICH | 0 | 1 | $10K |
| Apr 5, 1997 | Thunderstorm Wind | SYCAMORE | 0 | 1 | $0 |
| Jun 18, 1975 | Tornado | 0 | 1 | $250K |
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
Flash flooding or significant flooding was reported across much of DeKalb County, including street closures due to flooding, basement flooding and creek, stream and river flooding. Extensive flooding was reported in the Evergreen mobile home park near Sycamore. Street flooding was reported in Waterman, Hinckley and Shabbona.
Torrential rainfall led to flash flooding in parts of DeKalb. Numerous roads were closed with four feet of standing water. Several people had to be rescued from cars in high water. Numerous basements were flooded and a retail store on Sycamore Street was flooded. A dorm on the Northern Illinois University Campus was evacuated. Rainfall amounts ranged from 3 to 5 inches across DeKalb. The highest amount was 5.00 inches at 13th and Scyamore Street, before the gage overflowed.
An approximately seven mile swath of damage occurred on the south side of Dekalb which was consistent with 60 mph to occasionally 100 mph winds. Damage began near the intersection of Malta Road and Nelson Road and concluded near Lynch Road just south of Gurler Road. A warehouse on Harvestore Drive had a portion of the roof torn off along with a broken window. Some mobile homes in the parking lot were rolled or overturned.
Context
Risk, population and federal disasters
Relatively Low
FEMA NRI risk rating
100,703
Population (ACS)
$244K
Median home value
12
Federal declarations
| Declared | Incident | Title | Type |
|---|---|---|---|
| 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 |
| Mar 17, 2011 | Snowstorm | SEVERE WINTER STORM AND SNOWSTORM | DR |
| Oct 3, 2008 | Severe Storm | SEVERE STORMS AND FLOODING | DR |
| Sep 25, 2007 | Severe Storm | SEVERE STORMS AND FLOODING | DR |
Quick answers
Frequently asked
How many severe weather events have been recorded in DeKalb County, Illinois?
485 events are on record between 1957 and 2026, causing 2 direct deaths and $15.6M in property damage.
What is the most common severe weather hazard in DeKalb County?
Thunderstorm Wind, with 314 recorded events — 64.7% of everything in the archive for this county.
How many tornadoes have crossed DeKalb County?
31 mapped tornado paths intersect the county boundary; 25 of them touched down inside it. This is derived from path geometry, not county-tagged reports.
How many federal disaster declarations cover DeKalb County?
12 federal disaster declarations from FEMA include DeKalb County, each tied to a specific incident period.
How risky is DeKalb County compared with the rest of the country?
FEMA's National Risk Index rates DeKalb County as relatively low risk, placing it in the 81 percentile of its state for expected annual loss.
Where does the DeKalb 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
- Cumberland County 180
- De Witt County 259
- Crawford County 281
- Douglas County 266
- Cook County 2,633
- DuPage County 970
Cite this page
“DeKalb County, Illinois.” Severe Weather History. severeweatherhistory.com/county/illinois/dekalb-county/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.