Swansea

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond this area.
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.

Flood insurance figures are for St. Clair County, the county that contains Swansea.

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 in St. Clair County, the county that contains Swansea.

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.

The drought index is for St. Clair County, the county that contains Swansea.

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 city centre.
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

Landslides mapped in St. Clair County.

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. Jul 26, 2022Flash Flood$10.0 million
   National Weather Service narrative

   Up to 9 inches of rain fell in a 6 to 10 hour period causing widespread flash flooding. The heaviest rain axis extended from East St. Louis southeastward towards Mascoutah. Numerous roads were flooded, including northbound I-55 at I-64, ramps from I-64 to I-255, U.S. Highway 50 between O'Fallon and Lebanon, and Illinois Route 15 near intersection with Frank Scott Parkway. Several water rescues were performed including on Illinois Route 15 at Karch Road, east of Freeburg and on West F Street near North 3rd Street in Belleville. An estimated 600 St. Clair County households were damaged by flash flooding. The St. Clair County Animal Shelter was flooded in Belleville so several dozen…

2. Jun 2, 2019Flood$8.1 million
   National Weather Service narrative

   The Mississippi River at Alton, IL remained at it's highest levels between the evening of June 2nd and the evening of June 12th. There was at least $8.1 million in damage to the infrastructure along the Mississippi River due to the river flooding in St. Clair County.

3. Sep 8, 2001Thunderstorm Wind$600,000
   National Weather Service narrative

   Thunderstorm wind gusts of 75 to 80 mph hit the RV park at the Casino Queen overturning 6 recreational vehicles. Nine people were injured. Six were treated for minor injuries and released and 3 were kept overnight for observation. One of the RV's was overturned onto a vehicle, destroying both.

4. Mar 14, 2025Tornado$260,000
   National Weather Service narrative

   At approximately 10:30 PM, a tornado began near Scheve Park in Mascoutah. In Mascoutah the tornado caused roof damage to multiple residences as well as the local high school. Power poles and outbuildings were damaged as well. The most intense damage in town occurred near the intersection of Beechcraft Blvd and Fuesser Rd. The tornado continued northeast where it damaged a grain elevator and more farm outbuildings. The most significant damage in the county occurred near the Madison/Clinton County border where farm outbuildings were completely destroyed and residences sustained heavy roof and window damage. The tornado then crossed into Clinton County. In St. Clair County the…

5. Jul 18, 2000Flood$200,000
   National Weather Service narrative

   Heavy rain caused some localized flooding in Fairview Heights. A 30 by 35 foot section of roof on a department store at a shopping mall collapsed under the weight of about 3 inches of rain. About a foot of water on Route 159 stranded several motorists.

6. Mar 14, 2025Tornado$150,000
   National Weather Service narrative

   At approximately 10:28 PM a tornado began in the northeastern outskirts of O'Fallon, IL where it caused damage to multiple mobile homes, single family homes, outbuildings, and trees along its track northeast. The tornado then passed into southern Madison County. In Madison County the tornado was rated EF-1 with a path length of 6.75 miles and a maximum path width of 770 yards. In St. Clair County the tornado was rated EF-1 with a path length of 5.9 miles and a maximum path width of 450 yards.

7. Mar 14, 2025Thunderstorm Wind$150,000
   National Weather Service narrative

   Thunderstorm winds caused a home to collapse with two elderly residents inside.

8. Jun 11, 1999Thunderstorm Wind$100,000
   National Weather Service narrative

   Thunderstorm wind gusts blew a large sign off the roof of a mall. Pieces of the sign blew onto the parking lot damaging at least 20 cars. Trees and power lines were downed in the Belleville area.

9. May 19, 2022Thunderstorm Wind$60,000
   National Weather Service narrative

   Thunderstorm winds blew off part of the roof of a church on East Main Street near intersection with Walnut Street. Also, numerous tree limbs were blown down around Belleville. A large tree was blown onto a house in Shiloh causing moderate roof damage.

10. Oct 24, 2021Thunderstorm Wind$50,000
    National Weather Service narrative

    A swath of damaging winds occurred over St. Clair County from Swansea through O'Fallon, Scott AFB, and Mascoutah. Several large trees were blown down. The roof of a storage building was blown off at Air Force Base Storage. The debris landed on a house east of the storage building near the intersection of Illinois Route 161 and Hannah Chase Court. In Mascoutah, a pole barn was lifted and flipped, landing on a nearby business about 30 feet to the east.

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

110°FJul 14, 1954

All-time low

−27°FJan 17, 1977

Warmest night

88°F2 times, most recently May 19, 1996

Coldest day

−4°FDec 22, 1989

Wettest day

8.15 inJun 15, 1957

Snowiest day

14.8 inJan 31, 1982

Hottest year

2012mean 60.6°F

Coldest year

1979mean 53.1°F

Wettest year

200856.83 in

Driest year

195320.56 in

Snowiest season

36.6 in1981-82

Station Belleville Siu Rsch (USW00013802), 450 ft elevation, 7.9 miles from the city centre. Daily records from 1948 to October 25, 2026; 97.8% 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.

Declarations for St. Clair County.

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.

• 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 USW00013802.
• 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.