Jersey County, Illinois
Natural disaster risk, federal disaster history and flood insurance facts.
Jersey County, Illinois has a very low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 81% of US counties. It ranks 90th of 102 counties in Illinois. The costliest hazards here are inland flooding, heat waves and cold waves. FEMA estimates about $11 million a year in expected losses, or roughly $504 per resident. Since 1969 it has been included in 18 federal disaster or emergency declarations for natural events (16 major disasters). The most recent was in December 2021 (severe storms, straight-line winds and tornadoes). Fewer than 1 in 100 homes here carry federal flood insurance (72 policies). Since 1978, federal flood insurance has paid about $24 million on 1,869 claims here, including $8.0 million for floods in 1993.
FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.
Top risks in Jersey County
- Check the FEMA flood map for your address, and ask the seller or landlord about past flooding.
- Price a flood policy now. Most new federal policies take 30 days to start.
- Check that cooling works before summer.
- Know where the nearest cooling center is.
- Insulate pipes in outside walls, crawl spaces and garages.
- Know how to shut off the main water valve.
All 18 hazards
What the ratings mean ›| Hazard | Rating | Score | Expected loss a year | |
|---|---|---|---|---|
| Inland flooding | 18.0 | $3M | ||
| Heat wave | 79.3 | $2M | ||
| Cold wave | 53.7 | $2M | ||
| Tornado | 38.1 | $1M | ||
| Earthquake | 64.3 | $909K | ||
| Strong wind | 40.4 | $650K | ||
| Lightning | 41.0 | $257K | ||
| Hail | 35.6 | $231K | ||
| Drought | 45.5 | $160K | ||
| Landslide | 81.8 | $32K | ||
| Winter weather | 21.1 | $29K | ||
| Ice storm | 20.7 | $26K | ||
| Hurricane | 8.8 | $2K | ||
| Wildfire | 0.5 | $322 |
Scores are percentiles: a score of 90 means higher risk than about 90% of US counties for that hazard. Hazards FEMA does not rate here are left out. Social vulnerability is very low and community resilience is very high in FEMA's measures.
Federal disaster history
Recent disasters nationwide ›Declarations by decade
Federal declarations for natural events that included Jersey County. 2020s bar runs to November 2026.
By type
Most recent
Show all 18
Illinois also had 2 statewide declarations that did not name single counties.
Storm history since 1955
Tornado risk by county ›The National Weather Service has logged 253 storm reports in Jersey County since 1955, with 3 deaths and 2 injuries and about $5.9 million in reported damage. The strongest on record here was an F2 tornado on May 1, 1983.
Strongest tornadoes
| Date | Strength | Near | Hurt / killed |
|---|---|---|---|
| May 1, 1983 | F2 | – | 1 / 0 |
| May 1, 1983 | F2 | – | 1 / 0 |
| Mar 8, 2009 | EF2 | Rosedale | 0 / 0 |
| Sep 24, 1961 | F1 | – | 0 / 1 |
| Nov 15, 1988 | F1 | – | 0 / 0 |
Most damaging storms
| Date | Type | Near | Damage |
|---|---|---|---|
| May 1, 1983 | Tornado | – | $3M |
| May 1, 1983 | Tornado | – | $3M |
| Nov 15, 1988 | Tornado | – | $250K |
| Nov 27, 1990 | Tornado | – | $250K |
| May 22, 2011 | Lightning | Jerseyville | $150K |
| Apr 27, 2026 | Flash Flood | Jerseyville | $50K |
Source: NOAA Storm Events Database, county-based reports through Apr 27, 2026. Tornado records start in 1950, hail and wind in 1955, and floods and other storm types in 1996, so older decades undercount. Damage is in dollars of the year it happened and is often an estimate. Winter storms, heat and hurricanes are logged by forecast zone, not county, so they are not counted here.
Flood insurance in Jersey County
Check your address flood zone ›National Flood Insurance Program (NFIP) records only; private flood policies are not included. Home counts as of Aug 3, 2026. Since 2021 NFIP prices each home separately under Risk Rating 2.0, so your price depends on the building, not the county. Ask an agent for a quote.
Homes in Jersey County
Older homes and mobile homes usually suffer more damage in storms, floods and earthquakes, and can cost more to insure. If you are buying, ask about roof age, foundation bolting and any retrofits. Source: US Census Bureau, American Community Survey 2020 to 2024 5-year estimates; 9,958 housing units.
Compare in Illinois
All 102 ›| Largest counties | Overall risk | Top hazard |
|---|---|---|
| Cook County | Inland flooding | |
| DuPage County | Inland flooding | |
| Lake County | Inland flooding | |
| Will County | Inland flooding | |
| Kane County | Inland flooding | |
| McHenry County | Inland flooding | |
| Winnebago County | Inland flooding | |
| Madison County | Inland flooding |
Neighboring counties
| County | Overall risk | Declarations |
|---|---|---|
| St. Charles County, MO | 26 | |
| Madison County | 14 | |
| Macoupin County | 7 | |
| Greene County | 17 | |
| Calhoun County | 23 |
Common questions about Jersey County
What is the biggest natural hazard in Jersey County?
Inland flooding has the highest expected yearly losses in Jersey County, about $3.4 million a year in FEMA's estimate. Heat wave is second at $2.3 million.
How many federal disasters has Jersey County had?
Jersey County has been included in 18 federal disaster or emergency declarations for natural events since 1969, including 16 major disasters. The most recent was Severe Storms, Straight-Line Winds, and Tornadoes in December 2021.
Is Jersey County a high-risk place to live?
Its overall rating is Very Low, 90th highest of 102 in Illinois. A county rating covers the whole area. Risk at one address can be much higher or lower, so check the FEMA flood map and ask about the home's history.
Do I need flood insurance in Jersey County?
Standard home insurance does not cover flooding. About 1 in 111 homes in Jersey County has federal flood insurance. Lenders require it in mapped high-risk zones, but many flood claims come from outside those zones.
How many tornadoes has Jersey County had?
NOAA records list 22 tornadoes in Jersey County since 1950. The strongest was an F2 tornado on May 1, 1983. The weather service has also logged 85 hail reports and 28 floods here.
Sources: FEMA National Risk Index (December 2025), OpenFEMA Disaster Declarations Summaries, and NFIP policy and claims data. Hazard Compass is independent and not affiliated with FEMA. These figures describe the whole county, not a single property, and are not insurance or safety advice. Report a problem.