LaSalle County Hazard Profiles

Hazard	Days with reports, 1996–2025	Years with at least one	Deaths*	Injuries*	Property damage entered*
Thunderstorm wind	156	30/30	0	7	$593K
Hail	80	27/30	0	15	$1.0M
Tornado	19	17/30	10	55	$8.9M
Flooding	67	27/30	1	5	$88.0M
Winter storms	76	25/30	1	0	$2K
Lightning	15	9/30	0	10	$158K
High wind (no storm)	27	19/30	0	0	$379K

Year	Thunderstorm wind	Hail	Tornado	Flooding	Winter storms	Lightning	High wind (no storm)
1996	5	1	1	2	0	0	1
1997	5	1	1	1	1	0	1
1998	5	3	0	3	1	0	1
1999	2	2	0	0	2	1	0
2000	8	2	1	1	3	1	0
2001	4	3	0	1	0	1	1
2002	1	0	0	2	2	0	1
2003	10	9	1	0	1	2	2
2004	3	5	1	1	0	0	1
2005	4	1	0	2	0	1	0
2006	8	9	1	3	3	0	0
2007	7	2	0	5	3	2	2
2008	13	5	0	6	5	0	4
2009	6	1	0	5	1	2	0
2010	8	3	1	1	4	0	3
2011	4	6	0	6	1	4	1
2012	2	3	0	1	1	0	0
2013	7	4	2	2	1	0	0
2014	2	1	1	0	5	0	1
2015	6	3	1	2	4	0	1
2016	4	2	1	2	1	0	2
2017	6	3	1	1	0	0	1
2018	2	0	1	1	4	1	0
2019	3	2	0	4	7	0	1
2020	7	2	1	2	1	0	0
2021	3	1	1	2	5	0	1
2022	4	1	0	3	7	0	1
2023	4	4	2	1	2	0	1
2024	7	0	1	4	4	0	0
2025	6	1	0	3	7	0	0

	J	F	M	A	M	J	J	A	S	O	N	D
Thunderstorm wind		2	8	7	19	44	32	23	7	5	7	2
Hail	1	1	7	16	19	8	12	6	7	1	2
Tornado		1		3	4	5	2	1	1	1	1
Flooding	5	6	1	6	10	8	13	11	6	1
Winter storms	25	23	6	1						1	4	16
Lightning				1	2	3	4	4	1
High wind (no storm)	2	4	4	4	3	1			1	2	4	2

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 28 communities, most often Marseilles, Rutland and Earlville.
Extent: The strongest on record is the F3 of April 20, 2004 near Peru (8 deaths, 7 injuries). Tornadoes rated F2/EF2 or stronger touched down on 8 separate days.
Previous occurrences: 52 tornadoes on 29 days from 1984 to 2026. The busiest day was June 22, 2016, with 8. Weather Service survey, June 11, 2026: "A tornado which touched down near Long Point in Livingston County, moved northeast and crossed into LaSalle County just east of Prairie Grove Road and was likely at peak intensity as it crossed into LaSalle County as well as at its maximum width of 600 yards. The tornado heavily …"
Probability: At least one tornado in 17 of 30 years (57%) from 1996 to 2025.
Recorded losses: 10 deaths, 55 injuries, $8.9M in property damage as entered by the Weather Service (12 of 52 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 54 communities, most often Ottawa, Peru and Mendota.
Extent: The highest gust on record is 90 knots (104 mph), estimated near Oglesbey on October 3, 2000. 37 reports reached 65 knots (75 mph) or more.
Previous occurrences: 373 reports on 193 days since 1980. August 10, 2020: "A wind gust to 91 mph was measured. Roof damage was reported to homes; traffic signs were snapped; power lines were blown down and tree damage was reported."
Probability: Reports in 30 of 30 years (100%) from 1996 to 2025; about 5.2 damaging-wind days a year.
Recorded losses: 0 deaths, 7 injuries, $593K in property damage as entered by the Weather Service (50 of 373 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 33 communities, most often Ottawa, Marseilles and Streator.
Extent: Largest: 3.75 inches near Marseilles on July 13, 2015. 13 reports of 2 inches or more.
Previous occurrences: 168 reports on 96 days since 1984.
Probability: Reports in 27 of 30 years (90%) from 1996 to 2025.
Recorded losses: 0 deaths, 15 injuries, $1.0M in property damage as entered by the Weather Service (1 of 168 reports carries 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 28 communities, most often Mendota, Marseilles and Ottawa.
Extent: The deadliest flood on record was April 18, 2013 (1 death). The costliest entry is April 18, 2013, at $75.0M in property damage.
Previous occurrences: 91 flood, flash-flood and heavy-rain reports since 1996. August 17, 2025: "A personal weather station in Peru recorded 2.88 of rainfall in the two hour period between 5:15 and 7:15 PM CST. 1.85 fell in a 45 minute window between 5:15 and 6 PM CST."
Probability: Reports in 27 of 30 years (90%) from 1996 to 2025.
Recorded losses: 1 death, 5 injuries, $88.0M in property damage as entered by the Weather Service (17 of 91 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 2 occasions. Zone records rarely give snow or ice totals; the full plan adds station data.
Previous occurrences: 79 zone events from 1997 to 2026: 35 winter storm, 25 winter weather, 13 heavy snow, 4 blizzard, 2 ice storm.
Probability: Events in 25 of 30 years (83%) from 1996 to 2025.
Recorded losses: 1 death, 0 injuries, $2K in property damage as entered by the Weather Service (1 of 79 reports carries 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 8 communities, most often Ottawa, Peru and La Salle.
Extent: 0 deaths and 10 injuries on record.
Previous occurrences: 15 damaging strikes since 1999.
Probability: Damaging strikes in 9 of 30 years (30%) from 1996 to 2025.
Recorded losses: 0 deaths, 10 injuries, $158K in property damage as entered by the Weather Service (8 of 15 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: 60 knots (69 mph).
Previous occurrences: 30 zone events since 1996.
Probability: Events in 19 of 30 years (63%) from 1996 to 2025.
Recorded losses: 0 deaths, 0 injuries, $379K in property damage as entered by the Weather Service (13 of 30 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.

LaSalle County, Illinois
Hazard Profiles

At a glance

How often, year by year

When in the year

Tornado tracks, 1984–2026

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
Ottawa	51	21	9	2	4	87
Peru	35	13	6	2	3	59
Mendota	34	13	9	1	1	58
Streator	30	13	4	1		48
Marseilles	16	14	9	4		43
Earlville	14	11	2	4		31
La Salle	13	6	6		2	27
Lostant	16	5	3	2		26
Sheridan	9	4	1	2	1	17
Utica	10	4	1	1		16
Seneca	6	1	6			13
Rutland	3	3	2	4		12
Leland	8	3			1	12
Tonica	9	2			1	12
Oglesby	8	3	1			12
Illinois Valley	10					10
Lake Holiday	3	4	2			9
Serena	3	2	2	1		8