Hazard Mitigation Plan update · Section 4 draft · prepared October 3, 2026
Jersey County, Illinois Hazard Profiles
Draft. Built from public National Weather Service storm records (NOAA Storm Events, 1980 to June 2026). Not an adopted plan and not reviewed by FEMA.
Jersey County's plan, the Jersey County 2021 Hazard Mitigation Plan, expired May 10, 2026 in FEMA's plan-status data, with no update recorded as in progress on October 3, 2026. This chapter drafts the hazard-profile section of the update from 304 storm reports for the county, every one traceable to a NOAA event ID.
At a glance
7 hazards appear in the federal storm record for Jersey County. Thunderstorm wind is the most frequent; flooding accounts for the most recorded deaths and damage.
Hazard
Days with reports, 1996–2025
Years with at least one
Deaths*
Injuries*
Property damage entered*
Thunderstorm wind
61
27/30
0
0
$19K
Hail
43
23/30
0
0
$0
Tornado
10
9/30
0
2
$5.5M
Flooding
33
15/30
2
0
$160K
Winter storms
55
22/30
0
0
$0
Lightning
1
1/30
0
0
$150K
High wind (no storm)
8
7/30
0
0
$11K
* All years on record (tornado, wind and hail from the 1980s; other hazards from 1996). Dollars are as entered, not adjusted for inflation.
How often, year by year
Days with at least one report, 1996 to 2025. Each panel has its own scale. Hover a bar for the year.
Thunderstorm wind61 days · 27 of 30 yearsHail43 days · 23 of 30 yearsFlooding33 days · 15 of 30 yearsTornado10 days · 9 of 30 yearsWinter storms55 days · 22 of 30 yearsLightning1 day · 1 of 30 years
Show the numbers behind the charts
Year
Thunderstorm wind
Hail
Tornado
Flooding
Winter storms
Lightning
High wind (no storm)
1996
2
1
0
1
1
0
0
1997
0
1
0
0
3
0
1
1998
5
3
0
0
4
0
0
1999
2
1
0
0
2
0
0
2000
3
2
1
1
3
0
0
2001
3
1
0
4
1
0
2
2002
1
1
0
4
3
0
1
2003
2
4
0
3
2
0
0
2004
4
3
0
1
2
0
0
2005
3
2
1
1
1
0
0
2006
4
4
0
1
2
0
0
2007
3
1
1
2
5
0
0
2008
2
3
0
5
5
0
1
2009
2
1
1
0
0
0
1
2010
2
1
0
2
1
0
0
2011
2
3
0
0
3
1
0
2012
1
1
1
0
0
0
0
2013
0
1
0
4
2
0
0
2014
2
1
1
1
3
0
0
2015
2
3
0
1
4
0
0
2016
2
2
0
0
0
0
0
2017
1
1
1
0
0
0
0
2018
1
0
1
0
0
0
0
2019
1
0
0
2
2
0
1
2020
0
0
0
0
0
0
0
2021
1
0
0
0
1
0
0
2022
3
0
0
0
3
0
0
2023
3
2
0
0
0
0
0
2024
1
0
2
0
0
0
0
2025
3
0
0
0
2
0
1
When in the year
Days with reports by month, 1996 to 2025. Darker means more days.
J
F
M
A
M
J
J
A
S
O
N
D
Thunderstorm wind
2
4
6
14
11
10
8
1
3
1
1
Hail
5
1
10
14
8
1
3
1
Tornado
2
2
3
1
1
1
Flooding
1
4
11
7
2
4
1
1
2
Winter storms
19
15
6
1
3
11
Lightning
1
High wind (no storm)
1
3
1
1
1
1
Tornado tracks, 1983–2026
18 tornadoes. Lines run from touchdown to lift within the county; dots are tornadoes recorded at a single point. Hover a track for its date and rating.
F0/EF0F1/EF1F2/EF2F3 or strongerF5Unrated
County outline from the Census Bureau (simplified); community labels sit at the average location of reports naming them.
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 10 communities, most often Jerseyville, Rosedale and Fieldon.
Extent
The strongest on record is the F2 of May 1, 1983 (1 injury). Tornadoes rated F2/EF2 or stronger touched down on 2 separate days.
Previous occurrences
18 tornadoes on 14 days from 1983 to 2026. The busiest day was March 14, 2024, with 3. Weather Service survey, March 11, 2026: "A brief tornado was confirmed both with radar data and detailed photographs of damage. This tornado cause significant roof damage to a local restaurant, along with other miscellaneous to a local hotel and residence."
Probability
At least one tornado in 9 of 30 years (30%) from 1996 to 2025.
Recorded losses
0 deaths, 2 injuries, $5.5M in property damage as entered by the Weather Service (4 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 16 communities, most often Jerseyville, Grafton and Elsah.
Extent
The highest gust on record is 78 knots (90 mph), estimated near Beltrees on April 29, 2017. 2 reports reached 65 knots (75 mph) or more.
Previous occurrences
104 reports on 83 days since 1980. April 29, 2017: "A damaging microburst caused extensive damage to the Piasa Marina. One large boat dock was destroyed. An unoccupied building sustained moderate roof damage. Several trees were snapped off in an area extending from the marina northward …"
Probability
Reports in 27 of 30 years (90%) from 1996 to 2025; about 2.0 damaging-wind days a year.
Recorded losses
0 deaths, 0 injuries, $19K in property damage as entered by the Weather Service (10 of 104 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 14 communities, most often Jerseyville, Grafton and Otterville.
Extent
Largest: 2.5 inches near Jerseyville on April 27, 2026. 4 reports of 2 inches or more.
Previous occurrences
79 reports on 50 days since 1980.
Probability
Reports in 23 of 30 years (77%) from 1996 to 2025.
Recorded losses
0 deaths, 0 injuries, $0 in property damage as entered by the Weather Service (0 of 79 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 9 communities, most often Grafton, Nutwood and Jerseyville.
Extent
The deadliest flood on record was May 8, 2003 (1 death). The costliest entry is April 27, 2026, at $50K in property damage.
Previous occurrences
39 flood, flash-flood and heavy-rain reports since 1996. August 12, 2019: "Up to 4 inches of rain fell in less than 5 hours causing flash flooding. Numerous roads were flooded and several cars were stuck in high water. No injuries were reported."
Probability
Reports in 15 of 30 years (50%) from 1996 to 2025.
Recorded losses
2 deaths, 0 injuries, $160K in property damage as entered by the Weather Service (9 of 39 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
55 zone events from 1996 to 2025: 33 winter storm, 14 heavy snow, 3 ice storm, 3 winter weather, 2 sleet.
Probability
Events in 22 of 30 years (73%) from 1996 to 2025.
Recorded losses
0 deaths, 0 injuries, $0 in property damage as entered by the Weather Service (0 of 55 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 1 communities, most often Jerseyville.
Extent
0 deaths and 0 injuries on record.
Previous occurrences
1 damaging strikes since 2011.
Probability
Damaging strikes in 1 of 30 years (3%) from 1996 to 2025.
Recorded losses
0 deaths, 0 injuries, $150K in property damage as entered by the Weather Service (1 of 1 report carries 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: 50 knots (58 mph).
Previous occurrences
8 zone events since 1997.
Probability
Events in 7 of 30 years (23%) from 1996 to 2025.
Recorded losses
0 deaths, 0 injuries, $11K in property damage as entered by the Weather Service (2 of 8 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.
Previous occurrences by community
FEMA asks for hazard history for each participating jurisdiction. These are the communities the Weather Service names most often as the nearest place to a report.
Nearest community named in the report
Thunderstorm wind
Hail
Flooding
Tornado
Lightning
All
Jerseyville
30
22
3
2
1
58
Grafton
9
13
8
1
31
Elsah
9
4
1
1
15
Fieldon
4
7
1
2
14
Nutwood
3
3
5
11
Otterville
2
7
9
Rosedale
3
3
2
8
Delhi
3
2
1
2
8
Kemper
4
3
1
8
Dow
4
3
7
New Delhi
2
2
1
1
6
Fidelity
3
1
4
Monument
2
1
1
4
Beltrees
2
1
3
Mc Clusky
2
1
3
Newbern
1
1
2
Chautauqua
1
1
What this draft covers, and what the full update adds
Covered here
Type, location and extent of each recorded hazard (FEMA review element B1).
Previous occurrences and probability of future events, countywide and by community (element B2).
Added in the full update
Vulnerability and impacts on people, buildings and critical facilities from county parcel and building data (element B3).
National Flood Insurance Program repetitive-loss properties from FEMA (element B4).
Planning-team meetings, public input, capability review, the mitigation strategy and adoption.
Data notes
Before 1996 the storm database records only tornado, thunderstorm wind and hail, so every rate on this page uses 1996–2025.
Recent reports rarely carry a damage estimate: 6 of 26 wind, hail, tornado and flood reports since 2019 do. A missing dollar figure means "not estimated," not "no damage."
Reports follow people. Towns with more spotters and roads show more reports.
Winter storm, high wind and some flood events are recorded by forecast zone, not by point.