Riverdale

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.

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 Cook County, the county that contains Riverdale.

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 Cook County, the county that contains Riverdale.

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 Cook County, the county that contains Riverdale.

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.

Tsunamis

Tsunami records for Cook County.

1. Places where NOAA's Global Historical Tsunami Database records a tsunami's water arriving, with the greatest height it reached above sea level at the time. Only tsunamis NOAA rates probable or definite are counted. Heights from eyewitness accounts and tide gauges are mixed, and older events are less completely recorded.

NOAA NCEI/WDS Global Historical Tsunami Database, retrieved October 30, 2026.

More event types since 1996

Costliest events since 1996

1. Jul 2, 2023Flash Flood$500 million
   National Weather Service narrative

   Throughout much of central Cook County including Chicago and nearby suburbs, very heavy rainfall caused widespread flash flooding of roadways and structures. During a 12-hour period from 3 AM to 3 PM CST, storm total rainfall in Cook County ranged from 1-9 inches, with the highest amounts in central Cook County near the border of Chicago, Cicero, and Oak Park. The magnitude of this rainfall ranged from typical to extreme, with the peak rainfall estimated to have less than a 0.2% chance of occurring in a given year. Two distinct waves of heavy rainfall occurred in the Chicago area during this event, with each period of heavy rainfall corresponding to significant flooding.||The…

2. Jul 24, 2010Flash Flood$253 million
   National Weather Service narrative

   Very heavy rain fell across much of north central Cook County producing widespread flooding and flash flooding during the early morning hours of July 24th. Hundreds of streets and thousands of basements were flooded. Numerous homes were surrounded by flood waters with water damage on the first floor. Several hundred vehicles were submerged or floating in flood waters, many were a total loss. Areas that suffered some of the most widespread flooding and extensive damage included Westchester, Western Springs, La Grange, Oak Park, Bellwood, Riverside, Berwyn, Brookfield, Hillside and Forest Park. In Westchester, 40 residents were evacuted by boat when their homes were completed…

3. Aug 17, 2025Flash Flood$230 million
   National Weather Service narrative

   Roughly 40,000 structures sustained flood damage around the city of Chicago. The greatest impacts were felt across the southwest side near and east of Midway Airport, but reports came in from all across the city. Chicago alone accounted for approximately $230 million in flood damages.

4. Jul 25, 2025Flash Flood$200 million
   National Weather Service narrative

   Flash flooding was widespread across a narrow corridor in central Cook County roughly along and south of Interstate 55 with the heaviest rain falling near Midway Airport. An estimated 30,000 basements were flooded in Chicago, including in Chicago Lawn, West Lawn, Elsdon, Clearing, Garfield Ridge and Gage Park. Approximately 100 structures were damaged or destroyed from the flooding. Numerous roads and viaducts were flooded and closed. A person was reported trapped in a car that was stuck in a flooded viaduct near Gage Park, who needed to be rescued. Two to three feet of flood waters were reported on 47th Street between South Halsted Street and South Morgan Street. In Washington…

5. Aug 17, 2025Flash Flood$55.0 million
   National Weather Service narrative

   Flood damages were estimated at $55 million as around 10,000 structures flooded across Chicago's near southwest suburbs, including Riverside, Berwyn, Cicero, and Summit.

6. Aug 22, 2014Flash Flood$50.0 million
   National Weather Service narrative

   Major flooding impacted portions of the souhtwest suburbs of Chicago.|Numerous streets were flooded and impassable with several feet of water in Burbank and Oak Lawn. Numerous cars stalled in the flooded streets and many basements were inundated with water. Multiple lanes and the shoulder was flooded and closed on I-294 at Route 171. Over three feet of water was reported in the viaduct at Kedzie Avenue and 79th Street where a fire truck stalled trying to pass through.

7. Sep 17, 2023Flash Flood$50.0 million
   National Weather Service narrative

   Heavy rain caused significant flooding and flash flooding across portions of southeast Cook County. Hundreds of roads were flooded and numerous cars were stranded in the flood waters. Some of the worst flooding occurred in and around Calumet City and Dolton where hundreds of houses and buildings were surrounded by flood waters and some streets were littered with abandoned cars. Water rescues were reported but resulted in no injuries. Hundreds of basements were flooded in Calumet City and at least 30 basements were flooded in South Holland. While the highest measured rainfall report was 5.69 inches one mile north northeast of South Holland, radar estimated rainfall showed possibly…

8. Jul 17, 1996Flash Flood$44.7 million
9. Aug 2, 2001Flash Flood$37.0 million
   National Weather Service narrative

   Thunderstorms developed over northern Cook county between 6 and 7 am on the morning of Thursday August 2nd. The storms slowly moved southeast across central and eastern Cook county. The thunderstorms began to move out of southern Cook county between 10 and 11 am. Rain was falling at the rate of 3 to 4 inches per hour at some locations.Areas that had significant flooding include the Edens expressway at Pratt, where 6 to 8 feet of water covered the interstate and 3 cars were submerged. The Edens was closed from Touhy to Peterson. The Dan Ryan was closed and flooded between 83rd and 87th. Hubbard's cave was flooded and impassible. The underground parking garage at The Museum of…

10. Sep 13, 2008Flash Flood$35.0 million
    National Weather Service narrative

    Flooding was reported at the following locations, First Avenue west of Berwyn; Palatine Road in Wheeling; North Avenue at Interstate 290 in Elmhurst; Interstate 90 near O'Hare Airport; Touhy Avenue near Mt. Prospect was impassible; Interstate 94 at Pratt, and along Weller Creek at Elmhurst Road. Wilke Road between Kirchoff and Central was flooded in Arlington Heights. Several feet of water was reported covering some taxiways and gate areas at O'Hare Airport. Standing water was reported in streets and in fields in Evanston. Park Boulevard was under water with a stalled car near Streamwood, and Popular Creek flooded fields. In Northbrook, an overflowing stream flooded Green Park.…

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

107°FJun 1, 1934

All-time low

−25°FJan 20, 1985

Warmest night

84°F2 times, most recently Jul 30, 1999

Coldest day

−11°FJan 18, 1994

Wettest day

6.16 inJul 12, 1957

Snowiest day

17.6 inJan 2, 1999

Hottest year

2024mean 56.2°F

Coldest year

1978mean 48.2°F

Wettest year

201953.90 in

Driest year

196222.22 in

Snowiest season

89.7 in1978-79

Station Chicago Midway Airport 3SW (USC00111577), 620 ft elevation, 9.8 miles from the city centre. Daily records from 1928 to October 27, 2026; 99.9% 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 Cook 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 USC00111577.
• 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.
• Tsunamis NOAA NCEI/WDS Global Historical Tsunami Database.
• 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.