Live
Active alerts for this county
Heat Advisory
Winnebago; Boone; McHenry; Lake; Ogle; Lee; De Kalb; Kane; DuPage; La Salle; Kendall; Grundy; Kankakee; Livingston; Iroquois; Ford; Northern Cook; Central Cook; Southern Cook; Northern Will; Southern Will; Eastern Will; Lake; Porter; Newton; Jasper; Benton
McHenry County, Illinois severe weather history spans 654 recorded events between 1958 and 2026. The dominant hazard is thunderstorm wind, accounting for 53.7% of all recorded events. It ranks #467 nationally and #16 in Illinois.
654
Recorded events
7
Direct deaths
123
Direct injuries
$39.8M
Property damage
The record
What the McHenry County, Illinois severe weather history record shows
Across the archive, McHenry County, Illinois severe weather history averages 9.6 recorded events a year. The busiest stretch on record is the 2010s, with 199 events logged in that decade alone. Roughly 57 events fall before 1990 and 597 from 1990 onward — a gap that reflects the expansion of NOAA reporting practice as much as the weather itself.
The deadliest hazard in the McHenry County, Illinois record is tornado, responsible for 7 direct deaths. The costliest is tornado, with $32.8M 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 McHenry County
| Hazard | Events | Deaths | Damage | Max | Span |
|---|---|---|---|---|---|
| Thunderstorm Wind | 351 | 0 | $581K | 76 | 1960–2026 |
| Hail | 192 | 0 | $135K | 2.75 | 1972–2026 |
| Tornado | 26 | 7 | $32.8M | F4 | 1958–2024 |
| Lightning | 23 | 0 | $1.0M | 0 | 1996–2024 |
| Flood | 21 | 0 | $4.7M | 0 | 2002–2026 |
| Heavy Rain | 19 | 0 | $0 | 0 | 2007–2024 |
| Flash Flood | 17 | 0 | $550K | 0 | 1996–2024 |
| Funnel Cloud | 5 | 0 | $0 | 0 | 2009–2022 |
Decade by decade
McHenry County, Illinois severe weather history by decade
Reporting practice changed over time — early decades are undercounted, not calmer.
Tornado tracks
Paths crossing this county
30 mapped tornado paths intersect this county: 23 touched down inside it and 7 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 | 24 | 450 | 25.5 mi | Crossed in |
| 1965-04-11 | EF4 | 6 | 75 | 9.1 mi | Touched down here |
| 1967-04-21 | EF4 | 1 | 100 | 8.8 mi | Crossed in |
| 2008-01-07 | EF3 | 0 | 5 | 13.1 mi | Crossed in |
| 1958-10-08 | EF2 | 1 | 0 | 81.0 mi | Crossed in |
| 2010-11-22 | EF2 | 0 | 6 | 18.1 mi | Crossed in |
| 1978-08-15 | EF2 | 0 | 0 | 2.0 mi | Touched down here |
| 1963-04-19 | EF2 | 0 | 0 | 0.1 mi | Touched down here |
| 1959-10-08 | EF2 | 0 | 1 | 2.0 mi | Touched down here |
| 2023-07-12 | EF1 | 0 | 0 | 6.4 mi | Touched down here |
Significant events
Deadliest events on record in McHenry County
| Date | Type | Location | Deaths | Injuries | Damage |
|---|---|---|---|---|---|
| Apr 11, 1965 | Tornado | 6 | 75 | $0 | |
| Oct 9, 1958 | Tornado | 1 | 0 | $2.5M | |
| Apr 21, 1967 | Tornado | 0 | 40 | $25.0M | |
| Apr 21, 1967 | Tornado | 0 | 3 | $2.5M | |
| Jul 14, 1992 | Thunderstorm Wind | 0 | 2 | $0 | |
| Jun 25, 2024 | Lightning | MARENGO | 0 | 1 | $0 |
| Jan 7, 2008 | Tornado | CHEMUNG | 0 | 1 | $2.0M |
| Oct 8, 1959 | 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
Heavy rain fell across McHenry County and southeast Wisconsin between July 11th and July 13th which lead to major flooding along the Fox River. The river gage at the McHenry Lock & Dam crested at 7.60 feet on July 22nd, the second highest crest on record. Flood stage at the McHenry Lock & Dam is 4 feet. The river gage at the Algonquin Tailwater measured a record crest of 13.15 feet on July 24th. Flood stage at the Algonquin Tailwater is 9.5 feet. There were 557 homes affected with some amount of water from the river flooding.
Flooding continued from heavy rain and flash flooding from earlier on August 7th. Boot Creek overflowed at Hemmingson Road. Picnic tables floating near a car barn in three feet of water. Water flowing over the railway station platform. Many streets are closed due to flooding in Union. Marengo measured 5.10 inches of rain and Woodstock measured 4.35 inches of rain.
Intersection of Route 47 and 120 closed due to two feet of standing water. Willow and Clay Streets closed due to waist deep water. Police conducting rescues from stranded vehicles. Basement flooding was reported throughout Woodstock, and as many as 10 properties were flooded as a creek overflowed its banks in McHenry, IL.
Context
Risk, population and federal disasters
Relatively Moderate
FEMA NRI risk rating
312,591
Population (ACS)
$308K
Median home value
16
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 |
| Mar 13, 2008 | Snowstorm | RECORD SNOW AND NEAR RECORD SNOW | EM |
| Dec 29, 2006 | Snowstorm | SNOW | EM |
Quick answers
Frequently asked
How many severe weather events have been recorded in McHenry County, Illinois?
654 events are on record between 1958 and 2026, causing 7 direct deaths and $39.8M in property damage.
What is the most common severe weather hazard in McHenry County?
Thunderstorm Wind, with 351 recorded events — 53.7% of everything in the archive for this county.
How many tornadoes have crossed McHenry County?
30 mapped tornado paths intersect the county boundary; 23 of them touched down inside it. This is derived from path geometry, not county-tagged reports.
How many federal disaster declarations cover McHenry County?
16 federal disaster declarations from FEMA include McHenry County, each tied to a specific incident period.
How risky is McHenry County compared with the rest of the country?
FEMA's National Risk Index rates McHenry County as relatively moderate risk, placing it in the 91 percentile of its state for expected annual loss.
Where does the McHenry 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
- McDonough County 592
- McLean County 760
- Logan County 551
- Macon County 562
- Livingston County 418
- Macoupin County 527
Cite this page
“McHenry County, Illinois.” Severe Weather History. severeweatherhistory.com/county/illinois/mchenry-county/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.