Grundy County Hazard Profiles

Hazard	Days with reports, 1996–2025	Years with at least one	Injuries*	Property damage entered*
Thunderstorm wind	89	28/30	2	$5.5M
Hail	40	19/30	0	$605K
Tornado	11	9/30	13	$36.4M
Flooding	40	23/30	0	$26.8M
Winter storms	65	22/30	12	$400K
Lightning	8	7/30	0	$288K
High wind (no storm)	18	14/30	1	$102K

Year	Thunderstorm wind	Hail	Tornado	Flooding	Winter storms	Lightning	High wind (no storm)
1996	4	3	0	2	0	0	1
1997	4	1	0	1	1	0	2
1998	2	0	0	1	1	0	2
1999	3	1	0	0	2	0	0
2000	5	1	0	1	2	2	0
2001	3	0	0	0	0	0	1
2002	0	0	0	1	2	1	1
2003	6	5	0	1	0	0	1
2004	3	2	1	1	0	1	1
2005	3	1	0	2	0	0	0
2006	8	3	0	3	0	1	0
2007	3	3	0	3	5	0	0
2008	5	2	0	3	5	1	0
2009	1	0	0	5	1	1	0
2010	5	0	0	0	1	0	2
2011	4	3	0	1	1	0	0
2012	3	3	0	1	1	0	2
2013	5	3	2	1	1	1	0
2014	2	1	1	0	4	0	1
2015	3	3	1	2	3	0	0
2016	1	0	1	1	0	0	1
2017	2	0	1	0	0	0	1
2018	0	0	0	2	3	0	0
2019	1	2	0	3	5	0	1
2020	3	1	2	1	2	0	0
2021	3	0	0	2	5	0	0
2022	1	1	0	0	8	0	0
2023	2	0	1	0	2	0	0
2024	2	1	1	1	4	0	1
2025	2	0	0	1	6	0	0

	J	F	M	A	M	J	J	A	S	O	N	D
Thunderstorm wind	2		1	3	17	26	20	13	3	3		1
Hail			4	6	11	7	4	5	1	1	1
Tornado		1		1	3	3	2				1
Flooding	2	4	1	1	10	5	7	5	5
Winter storms	23	21	5	1						1	1	13
Lightning					3	1	2	2
High wind (no storm)	2	4	4	2				1	1	1	2	1

Hazard profiles

Each profile answers FEMA's questions for hazard identification: what it is, where, how bad (extent), what has happened, and how likely it is to happen again.

Tornado

Description: A violently rotating column of air in contact with the ground, rated after the fact on the Fujita scale (through January 2007) or the Enhanced Fujita scale, EF0 to EF5, by the damage it leaves.
Location: Countywide; tornado reports name 11 communities, most often Gorman, Minooka and Central City.
Extent: The strongest on record is the EF3 of June 22, 2015 near Paytonville (7 injuries). Tornadoes rated F2/EF2 or stronger touched down on 4 separate days.
Previous occurrences: 18 tornadoes on 15 days from 1984 to 2024. The busiest day was June 22, 2015, with 3. Weather Service survey, July 15, 2024: "A tornado with estimated peak winds of 130 mph touched down along Bungalow Road, east of Gun Club Road producing sporadic tree damage. The tornado moved east northeast along the Illinois River and just before it crossed into Will County, the tornado expanded in size and was …"
Probability: At least one tornado in 9 of 30 years (30%) from 1996 to 2025.
Recorded losses: 0 deaths, 13 injuries, $36.4M in property damage as entered by the Weather Service (8 of 18 reports carry a dollar figure).

Severe thunderstorm wind

Description: Straight-line winds from thunderstorms, including downbursts, measured or estimated at 58 mph (50 knots) or more.
Location: Countywide; reports name 25 communities, most often Morris, Coal City and Mazon.
Extent: The highest gust on record is 78 knots (90 mph), estimated near Morris on June 30, 2014. 23 reports reached 65 knots (75 mph) or more.
Previous occurrences: 189 reports on 116 days since 1980. June 30, 2014: "Straight line winds of 80 to 90 mph caused a tremendous amount of tree damage across all of Morris. Numerous utility poles were snapped and power lines were blown down. Numerous roads were blocked. An estimated 90 percent of the city was …"
Probability: Reports in 28 of 30 years (93%) from 1996 to 2025; about 3.0 damaging-wind days a year.
Recorded losses: 0 deaths, 2 injuries, $5.5M in property damage as entered by the Weather Service (39 of 189 reports carry a dollar figure).

Hail

Description: Ice stones from thunderstorm updrafts; reported at 3/4 inch and larger in this record.
Location: Countywide; reports name 13 communities, most often Morris, Coal City and Mazon.
Extent: Largest: 2.75 inches near Minooka on June 10, 2015. 1 report of 2 inches or more.
Previous occurrences: 75 reports on 52 days since 1980.
Probability: Reports in 19 of 30 years (63%) from 1996 to 2025.
Recorded losses: 0 deaths, 0 injuries, $605K in property damage as entered by the Weather Service (3 of 75 reports carry a dollar figure).

Flooding (river, flash and heavy rain)

Description: River flooding, and flash flooding when heavy rain overwhelms streets, ditches and small streams.
Location: Countywide; reports name 16 communities, most often Morris, Nettlecreek and Coal City.
Extent: The costliest entry is April 18, 2013, at $15.0M in property damage.
Previous occurrences: 53 flood, flash-flood and heavy-rain reports since 1996. July 30, 2025: "Storm total rainfall of 3.35 inches was measured by a private weather station with most of the rain falling in 45 minutes."
Probability: Reports in 23 of 30 years (77%) from 1996 to 2025.
Recorded losses: 0 deaths, 0 injuries, $26.8M in property damage as entered by the Weather Service (13 of 53 reports carry a dollar figure).

Winter storms and ice

Description: Heavy snow, blizzards, ice storms, sleet and lesser winter weather, recorded by forecast zone rather than by point.
Location: Countywide (forecast-zone records).
Extent: Ice storms on 3 occasions. Zone records rarely give snow or ice totals; the full plan adds station data.
Previous occurrences: 68 zone events from 1997 to 2026: 30 winter weather, 21 winter storm, 9 heavy snow, 4 blizzard, 3 ice storm, 1 sleet.
Probability: Events in 22 of 30 years (73%) from 1996 to 2025.
Recorded losses: 0 deaths, 12 injuries, $400K in property damage as entered by the Weather Service (2 of 68 reports carry a dollar figure).

Lightning

Description: Cloud-to-ground strikes that injure people, start fires or damage property. Only damaging strikes are recorded.
Location: Countywide; reports name 5 communities, most often Morris, Minooka and South Wilmington.
Extent: 0 deaths and 0 injuries on record.
Previous occurrences: 9 damaging strikes since 2000.
Probability: Damaging strikes in 7 of 30 years (23%) from 1996 to 2025.
Recorded losses: 0 deaths, 0 injuries, $288K in property damage as entered by the Weather Service (8 of 9 reports carry a dollar figure).

High wind (not from thunderstorms)

Description: Strong winds from large storm systems rather than thunderstorms, recorded by forecast zone.
Location: Countywide (forecast-zone records).
Extent: Highest: 59 knots (68 mph).
Previous occurrences: 19 zone events since 1996.
Probability: Events in 14 of 30 years (47%) from 1996 to 2025.
Recorded losses: 0 deaths, 1 injury, $102K in property damage as entered by the Weather Service (5 of 19 reports carry a dollar figure).

Not covered by this record

Extreme heat, extreme cold, drought, earthquake and dam failure are not in the storm archive this chapter draws on. The full chapter profiles them from NOAA climate records, the U.S. Drought Monitor, USGS shaking maps and the state dam inventory, and the planning team decides which belong in the plan.

Grundy County, Illinois
Hazard Profiles

At a glance

How often, year by year

When in the year

Tornado tracks, 1984–2024

Hazard profiles

Tornado

Severe thunderstorm wind

Hail

Flooding (river, flash and heavy rain)

Winter storms and ice

Lightning

High wind (not from thunderstorms)

Not covered by this record

Previous occurrences by community

What this draft covers, and what the full update adds

Covered here

Added in the full update

Data notes

Nearest community named in the report	Thunderstorm wind	Hail	Flooding	Tornado	Lightning	All
Morris	60	25	9	1	4	99
Coal City	20	11	5			36
Mazon	20	8	1		1	30
Minooka	12	6	3	2	2	25
Gardner	6	5	1		1	13
Carbon Hill	5		5			10
Verona	8	1	1			10
Nettlecreek			7	1		8
Kinsman	1	4	2			7
Channahon	4	1	1			6
Braceville	3		2			5
Paytonville	2		2	1		5
Langham	1		3	1		5
Wauponsee	5					5
South Wilmington	2	1			1	4
Gorman		1		3		4
Sank Ridge		1	2	1		4
Dwight	2		1			3