Warren County, Illinois
Natural disaster risk, federal disaster history and flood insurance facts.
Warren County, Illinois has a very low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 84% of US counties. It ranks 92nd of 102 counties in Illinois. The costliest hazards here are inland flooding, cold waves and drought. FEMA estimates about $7.0 million a year in expected losses, or roughly $417 per resident. Since 1993 it has been included in 7 federal disaster or emergency declarations for natural events (5 major disasters). The most recent was in August 2023 (severe storms and flooding). Only 26 homes here carry federal flood insurance. Since 1978, federal flood insurance has paid about $193,000 on 26 claims here.
FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.
Top risks in Warren 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.
- Insulate pipes in outside walls, crawl spaces and garages.
- Know how to shut off the main water valve.
- Check local water restrictions.
- Choose drought-tolerant plants.
All 18 hazards
What the ratings mean ›| Hazard | Rating | Score | Expected loss a year | |
|---|---|---|---|---|
| Inland flooding | 11.0 | $2M | ||
| Cold wave | 53.5 | $1M | ||
| Drought | 81.9 | $1M | ||
| Heat wave | 65.8 | $864K | ||
| Strong wind | 46.1 | $564K | ||
| Tornado | 28.5 | $529K | ||
| Hail | 65.4 | $526K | ||
| Lightning | 36.7 | $164K | ||
| Ice storm | 55.0 | $123K | ||
| Earthquake | 34.4 | $122K | ||
| Winter weather | 32.9 | $39K | ||
| Hurricane | 17.5 | $6K | ||
| Landslide | 49.8 | $2K | ||
| Wildfire | 0.2 | $91 |
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 relatively 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 Warren County. 2020s bar runs to November 2026.
By type
Most recent
Illinois also had 2 statewide declarations that did not name single counties.
Storm history since 1958
Tornado risk by county ›The National Weather Service has logged 306 storm reports in Warren County since 1958, with 1 death and 1 injury and about $7.7 million in reported damage. The strongest on record here was an F2 tornado on September 26, 1959.
Strongest tornadoes
| Date | Strength | Near | Hurt / killed |
|---|---|---|---|
| Sep 26, 1959 | F2 | – | 0 / 1 |
| Jul 16, 2015 | EF2 | Nemo | 1 / 0 |
| Jul 16, 2015 | EF2 | Kirkwood | 0 / 0 |
| Apr 18, 1963 | F2 | – | 0 / 0 |
| Apr 5, 1999 | F2 | Swan Creek | 0 / 0 |
Most damaging storms
| Date | Type | Near | Damage |
|---|---|---|---|
| May 8, 2003 | Hail | Monmouth | $2M |
| Jul 16, 2015 | Tornado | Nemo | $2M |
| May 4, 2003 | Flash Flood | Monmouth | $1M |
| Sep 11, 2000 | Thunderstorm Wind | Monmouth | $500K |
| May 10, 2003 | Hail | Countywide | $500K |
| May 10, 2003 | Tornado | Youngstown | $300K |
Source: NOAA Storm Events Database, county-based reports through Jul 20, 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 Warren 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 Warren 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; 7,587 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 |
|---|---|---|
| Knox County | 9 | |
| Fulton County | 18 | |
| McDonough County | 9 | |
| Mercer County | 13 | |
| Henderson County | 14 |
Common questions about Warren County
What is the biggest natural hazard in Warren County?
Inland flooding has the highest expected yearly losses in Warren County, about $1.7 million a year in FEMA's estimate. Cold wave is second at $1.2 million.
How many federal disasters has Warren County had?
Warren County has been included in 7 federal disaster or emergency declarations for natural events since 1993, including 5 major disasters. The most recent was Severe Storms and Flooding in August 2023.
Is Warren County a high-risk place to live?
Its overall rating is Very Low, 92nd 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 Warren County?
Standard home insurance does not cover flooding. About 1 in 250 homes in Warren 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 Warren County had?
NOAA records list 36 tornadoes in Warren County since 1950. The strongest was an F2 tornado on September 26, 1959. The weather service has also logged 75 hail reports and 26 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.