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LaSalle County, Illinois severe weather history spans 753 recorded events between 1955 and 2026. The dominant hazard is thunderstorm wind, accounting for 51.8% of all recorded events. It ranks #340 nationally and #10 in Illinois.
753
Recorded events
11
Direct deaths
86
Direct injuries
$99.2M
Property damage
The record
What the LaSalle County, Illinois severe weather history record shows
Across the archive, LaSalle County, Illinois severe weather history averages 10.6 recorded events a year. The busiest stretch on record is the 2000s, with 251 events logged in that decade alone. Roughly 78 events fall before 1990 and 675 from 1990 onward — a gap that reflects the expansion of NOAA reporting practice as much as the weather itself.
The deadliest hazard in the LaSalle County, Illinois record is tornado, responsible for 10 direct deaths. The costliest is flash flood, with $81.8M 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 LaSalle County
| Hazard | Events | Deaths | Damage | Max | Span |
|---|---|---|---|---|---|
| Thunderstorm Wind | 390 | 0 | $593K | 90 | 1960–2026 |
| Hail | 175 | 0 | $1.0M | 3.75 | 1957–2026 |
| Tornado | 64 | 10 | $9.5M | F3 | 1955–2026 |
| Flood | 41 | 0 | $6.2M | 0 | 1998–2025 |
| Flash Flood | 36 | 1 | $81.8M | 0 | 1996–2025 |
| Funnel Cloud | 22 | 0 | $0 | 0 | 1996–2025 |
| Lightning | 15 | 0 | $158K | 0 | 1999–2018 |
| Heavy Rain | 10 | 0 | $0 | 0 | 2009–2025 |
Decade by decade
LaSalle County, Illinois severe weather history by decade
Reporting practice changed over time — early decades are undercounted, not calmer.
Tornado tracks
Paths crossing this county
68 mapped tornado paths intersect this county: 56 touched down inside it and 12 crossed in from a neighbouring county. This comes from path geometry, not county-tagged reports.
| Date | Scale | Deaths | Injuries | Path length | Origin |
|---|---|---|---|---|---|
| 2013-11-17 | EF4 | 3 | 125 | 46.4 mi | Crossed in |
| 2004-04-20 | EF3 | 8 | 12 | 15.8 mi | Crossed in |
| 2017-02-28 | EF3 | 2 | 14 | 11.5 mi | Touched down here |
| 1951-12-06 | EF3 | 1 | 1 | 21.9 mi | Crossed in |
| 2017-02-28 | EF3 | 0 | 0 | 17.8 mi | Crossed in |
| 1977-06-30 | EF3 | 0 | 0 | 6.1 mi | Touched down here |
| 1972-07-17 | EF3 | 0 | 0 | 81.5 mi | Crossed in |
| 2017-02-28 | EF2 | 0 | 0 | 5.6 mi | Touched down here |
| 2016-06-22 | EF2 | 0 | 0 | 8.1 mi | Touched down here |
| 2010-06-05 | EF2 | 0 | 17 | 17.6 mi | Crossed in |
Significant events
Deadliest events on record in LaSalle County
| Date | Type | Location | Deaths | Injuries | Damage |
|---|---|---|---|---|---|
| Apr 20, 2004 | Tornado | PERU | 8 | 7 | $0 |
| Feb 28, 2017 | Tornado | UTICA AIRPARK ARPT | 2 | 14 | $0 |
| Apr 18, 2013 | Flash Flood | LAKE HOLIDAY | 1 | 0 | $75.0M |
| Jun 6, 2010 | Tornado | EAST WENONA | 0 | 17 | $7.0M |
| May 15, 1985 | Hail | 0 | 14 | $0 | |
| Jul 10, 1985 | Tornado | 0 | 8 | $250K | |
| Sep 14, 2008 | Flood | LAKE HOLIDAY | 0 | 5 | $15K |
| May 17, 1999 | Lightning | LA SALLE | 0 | 5 | $0 |
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
The first area of significant damage in the EF2 range was in the area around the La Salle County Nursing Home and La Salle County Highway Department, with lighter damage upstream from this location. The tornado continued into Naplate and produced widespread EF2 damage to numerous homes. EF3 damage also was identified in two locations. The first was where a minivan was thrown about 30 yards and a home was lifted off its foundation and left with only its interior walls intact. The second was at the Pilkington Glass plant where one section of the factory was completely destroyed. The tornado then crossed the Illinois River and moved through the south side of Ottawa, producing an 800 yard wide path of EF1 damage to trees and homes. The fatalities in Ottawa occurred from a tree falling onto two men who were working outside. The tornado then crossed the Illinois River again and continued to produce EF1 and EF0 damage as it exited Ottawa, finally dissipating in the area northwest of Marseilles. (Tornado #2 of 7).
County emergency managers estimated that over 500 buildings were damaged by flooding across La Salle County. In Marseilles, 1500 people were evacuated due to a compromised levee which led to dozens of homes and facilities being flooded along the river front. Several barges broke loose from a tugboat on the Illinois River and rammed into the levee. Five of the eight locks were damaged such that they could not close completely. Flooding occurred in Utica east of Route 178 resulting in evacuations on the I&M Canal. Creeks were reported out of their banks in Mendota. A woman was killed on Route 351 as it passes over the Illinois River near Peru. She drove around barricades and became stranded in knee-deep water. Her body was found about two weeks later approximately 70 yards downstream.
The Illinois River reached a record crest of 33.79 feet at LaSalle on the 16th. Major flooding occurred along the river in LaSalle County. In Marseilles, flood waters inundated Illini State Park and nearby areas. Flood waters inundated the Peru power plant. Brunner and Water Streets were closed due to flooding. Navigation on the river was halted as most lock facilities were submerged. The Interstate 39 bridge was the only one open as State Highways 251, 351, and 178 were closed. Homes and businesses in Utica were flooded. In Ottawa, 89 residents of a nursing home were evacuated. Dee Bennett Road between Ottawa and Utica was closed. Central Elementary School in Ottawa was surrounded by water and the auditorium was flooded with 8 inches of water.
Context
Risk, population and federal disasters
Relatively Moderate
FEMA NRI risk rating
108,714
Population (ACS)
$162K
Median home value
20
Federal declarations
| Declared | Incident | Title | Type |
|---|---|---|---|
| Mar 26, 2020 | Biological | COVID-19 PANDEMIC | DR |
| Mar 13, 2020 | Biological | COVID-19 | EM |
| Nov 26, 2013 | Tornado | SEVERE STORMS, STRAIGHT-LINE WINDS, AND TORNADOES | DR |
| 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 |
Within the county
Most affected places
- Ottawa 103
Quick answers
Frequently asked
How many severe weather events have been recorded in LaSalle County, Illinois?
753 events are on record between 1955 and 2026, causing 11 direct deaths and $99.2M in property damage.
What is the most common severe weather hazard in LaSalle County?
Thunderstorm Wind, with 390 recorded events — 51.8% of everything in the archive for this county.
How many tornadoes have crossed LaSalle County?
68 mapped tornado paths intersect the county boundary; 56 of them touched down inside it. This is derived from path geometry, not county-tagged reports.
How many federal disaster declarations cover LaSalle County?
20 federal disaster declarations from FEMA include LaSalle County, each tied to a specific incident period.
How risky is LaSalle County compared with the rest of the country?
FEMA's National Risk Index rates LaSalle County as relatively moderate risk, placing it in the 86 percentile of its state for expected annual loss.
Where does the LaSalle 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
- Lake County 641
- Lawrence County 280
- Knox County 393
- Lee County 389
- Kendall County 365
- Livingston County 418
Cite this page
“LaSalle County, Illinois.” Severe Weather History. severeweatherhistory.com/county/illinois/lasalle-county/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.