Jersey County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Jersey County: 1.
2. Weak tornadoes were under-recorded before Doppler radar coverage became national in the early 1990s, so earlier decades read low. Ratings use the Fujita scale before February 2007 and the Enhanced Fujita scale after.

Storm Prediction Center severe weather database, 1950 to 2025.

Every storm within 100 miles

1. Tropical storms and hurricanes (34 kt or more, still tropical) at closest approach. Post-tropical remnants with gale-force winds are listed but not counted. Direct: track within 50 miles; near: within 100 miles. Distance is measured to the county boundary for counties and to the city centre for cities, using positions interpolated hourly between HURDAT2 fixes.

National Hurricane Center HURDAT2, 1851 to 2025.

Smoke overhead

1. A smoke day is a date on which a smoke plume traced by NOAA Hazard Mapping System analysts from satellite imagery covered this place's point (the county's population centre or the city centre). Counts here are of medium or heavy smoke. Since 2018 analysts have often drawn light smoke as one area over most of the continent, so light-smoke counts are not comparable from year to year. The plumes show smoke anywhere in the air above, not air quality at the ground, and smoke hidden by cloud is missed.

NOAA Hazard Mapping System smoke analysis, 2011 to 2026, retrieved October 30, 2026.

Claims by ZIP code

This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).

OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026. NOAA Storm Events through 2026.

River crests

River gauges

1. Crests are the highest and the recent crests the National Weather Service lists for each river gauge in the county that has a flood stage, not every flood. Flood categories use each gauge's current flood stages; crests from before levees, dams or channel changes may not be comparable. Crests measured on an old datum are left out of the rankings.

NOAA National Water Prediction Service gauge records, retrieved October 30, 2026.

1. The Palmer Drought Severity Index is computed by NOAA each month from the county's average temperature and precipitation, relative to the county's own climate. Zero is normal; -3 or lower is severe drought and -4 or lower extreme drought. It describes the long-term balance of moisture, not water supply or crop losses.

NOAA NCEI nClimDiv county Palmer Drought Severity Index, 1895 to September 2026, issued October 6, 2026.

Every earthquake of magnitude 4 or more within 50 miles

1. Earthquakes of magnitude 2.5 or more in the USGS Comprehensive Catalog since 1900. Within 50 miles means the epicentre lies within 50 miles of the county boundary (or inside the county).
2. Small earthquakes were under-recorded before the modern seismic networks of the 1970s and are still missed in remote areas, so early decades read low. Magnitudes are as the catalogue reports them and mix scales (moment, local and body-wave).

USGS ANSS Comprehensive Earthquake Catalog, 1900 to present, retrieved October 30, 2026.

Mapped landslides

Mapped by NASA (1).

1. Landslides mapped in the USGS compilation of landslide inventories across the United States (version 3.0, 2025), rated probable or better. The compilation joins inventories made by federal and state agencies for different purposes and areas, so the number mapped in a county reflects how closely it has been surveyed as much as how often its slopes fail. An area with few records may simply not have been mapped. Deaths are as recorded in the inventories; a slide listed in two inventories is counted once.

USGS Landslide Inventories across the United States, version 3.0, retrieved October 27, 2026.

More event types since 1996

Costliest events since 1996

1. May 22, 2011Lightning$150,000
   National Weather Service narrative

   Lightning struck a house causing a fire that destroyed the house. Fortunately the owners were not home at the time, so no injuries were reported.

2. Apr 27, 2026Flash Flood$50,000
   National Weather Service narrative

   Heavy rain washed out a culvert and damaged Green Acres Road near Elsah.

3. Apr 27, 2026Flash Flood$50,000
   National Weather Service narrative

   Heavy rain washed out a culvert and a portion of West County Road was washed out.

4. May 10, 2007Flash Flood$45,000
   National Weather Service narrative

   Local law enforcement reported flash flooding across Jerseyville. On the west side of town, Maple Summit Road was covered by 3 feet of water, and by 2 1/2 feet by the hospital.

5. Mar 14, 2025High Wind, Jersey$10,000
   National Weather Service narrative

   Wind gusts near 60 mph caused minor damage across the county. A farm out building was blown over near Jerseyville.

6. Dec 10, 2021Thunderstorm Wind$5,000
   National Weather Service narrative

   Thunderstorm winds blew down a metal sign and numerous tree limbs on the east side of town along Illinois Route 16.

7. Apr 19, 2013Flood$5,000
   National Weather Service narrative

   The Illinois River hit major flood levels along the border of Jersey County. The river crested around the 27th, but remained at major flood levels into May.

8. Apr 14, 2013Flood$5,000
   National Weather Service narrative

   The Mississippi River reached major flood levels along the border of Jersey County. The river crested on April 25th, but remained above flood stage into May. Damage was limited to a few closed roads.

9. Aug 3, 2022Thunderstorm Wind$5,000
   National Weather Service narrative

   Thunderstorm winds blew down several large trees.

10. Mar 5, 2022Thunderstorm Wind$5,000
    National Weather Service narrative

    Thunderstorm winds blew over a large outside play structure that was anchored. Also, numerous large tree limbs were blown down in the area.

1. Storm Events records before 1996 cover only tornadoes, thunderstorm wind and hail. Damage figures are as reported by the National Weather Service at the time, not adjusted for inflation.

NOAA NCEI Storm Events Database, 1950 to 2026, issued October 26, 2026.

All-time high

112°F2 times, most recently Jul 15, 1954

All-time low

−25°FJan 17, 1977

Warmest night

80°F2 times, most recently Jul 14, 1981

Coldest day

−8°FDec 25, 1983

Wettest day

5.81 inAug 11, 1961

Snowiest day

12.0 in3 times, most recently Jan 6, 2014

Hottest year

1953mean 57.3°F

Coldest year

2014mean 50.4°F

Wettest year

200862.64 in

Driest year

198024.43 in

Snowiest season

45.7 in1977-78

Station Jerseyville 2 Sw (USC00114489), 610 ft elevation, 2.3 miles from the population centre. Daily records from 1940 to October 27, 2026; 94.8% of days in the last 30 years are complete. Records at a single station can differ from a city’s official threaded record, which may combine several stations.

NOAA NCEI Global Historical Climatology Network Daily.

This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).

OpenFEMA Disaster Declarations Summaries, retrieved October 30, 2026. Statewide declarations are not listed.

Neighbouring counties

• Tornadoes NOAA Storm Prediction Center severe weather database, through 2025.
• Tropical cyclones NOAA National Hurricane Center HURDAT2 (Atlantic; Northeast and Central Pacific), through 2025.
• Wildfire USGS/USFS Monitoring Trends in Burn Severity, through 2026.
• Storm events NOAA NCEI Storm Events Database, through 2026.
• Flood insurance OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026.
• Declarations OpenFEMA Disaster Declarations Summaries v2, retrieved October 30, 2026.
• Weather records NOAA NCEI Global Historical Climatology Network Daily, station USC00114489.
• River crests NOAA National Weather Service, National Water Prediction Service river gauges, retrieved October 30, 2026.
• Drought NOAA NCEI nClimDiv county Palmer Drought Severity Index, through September 2026.
• Smoke NOAA NESDIS Hazard Mapping System smoke analysis, retrieved October 30, 2026.
• Landslides USGS Landslide Inventories across the United States, version 3.0 (2025).
• Earthquakes USGS ANSS Comprehensive Earthquake Catalog (ComCat), retrieved October 30, 2026.

Joins, thresholds and known limits are set out in the methodology. Found an error? Report it. Page built October 30, 2026.