Grundy County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Grundy County: 0.
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.

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.

More event types since 1996

Costliest events since 1996

1. Jun 22, 2015Tornado$25.0 million
   National Weather Service narrative

   The tornado touched down near Higgins Road and Dupont Road where softwood trees were snapped. The tornado moved east-southeast where trees and power poles were snapped along N Gorman Road. The most significant damage was noted as the tornado crossed S Carbon Hill Road just south of Division Street, entering Coal City. Dozens of homes were heavily damaged in Coal City with three completely destroyed. Two of these homes were well built and had at least part of their structure bolted down to the foundation with bolts secured by nuts. Two high tension metal trusses were downed including one that was crumpled along Hunters Run. Hundreds of trees were snapped or uprooted. Numerous…

2. Apr 18, 2013Flash Flood$15.0 million
   National Weather Service narrative

   The hardest hit areas in Grundy County were Morris, Mazon, and Minooka. Numerous rescues took place, including people trapped in vehicles in rising waters. Forty-four patients at Morris Hospital were evacuated when the lower floor flooded. The aqueduct that carries the I & M canal over Nettle Creek collapsed. South of Morris, Pine Bluff Road was impassable with approximately a foot of water.

3. Nov 17, 2013Tornado$10.8 million
   National Weather Service narrative

   The tornado formed just northwest of the intersection of E Braceville Road and S Carbon Hill Road where several softwood trees were uprooted. The tornado moved northeast just north of E Reed Road where a single family residence sustained visible damage to its exterior while a metal outbuilding sustained roof and exterior wall damage. A single family home sustained considerable damage near the intersection of Berta Road and Spring Road where two people were injured. The tornado continued into a subdivision north of Spring Road where widespread minor damage occurred to several dozen homes. Several homes received more substantial damage though, including partial loss of roofs and…

4. Sep 14, 2008Flash Flood$5.0 million
   National Weather Service narrative

   Flash flooding or significant flooding was reported across most of Grundy County, including street closures due to flooding, basement flooding and creek, stream and river flooding. Significant flooding was reported in Coal City.

5. Sep 15, 2008Flood$3.0 million
   National Weather Service narrative

   The Illinois River reached a record crest of 24.84 feet at Morris on the 16th. In Morris, flood waters inundated large areas near the river including the public works facilities and sewage treatment facilities. Water surrounded Ravine Woods apartment complex and residents had to be evacuated. Residents were also evacuated from homes on the east side of Morris along Cemetery Road.

6. Jul 7, 2003Thunderstorm Wind$2.5 million
   National Weather Service narrative

   Thunderstorms brought damaging winds to portions of north central and northeast Illinois during the evening of July 7th. In Lee county 60 mph winds were reported at I-39 and U.S. 30 and trees were blown down southeast of the I-88/I-39 interchange. In DeKalb county, trees were reported down in DeKalb, Sycamore, and Cortland. A tree fell onto two cars in Waterman in DeKalb county, completely destroying both cars. In LaSalle county, trees, tree limbs and power lines were blown down in Leland, Earlville, Lostant, and Streator. Five miles southeast of Ransom, a 60 mph wind gust was reported. An 85 foot tall tree was blown down on a house in Wedron. Trees were damaged in Plano in…

7. Aug 24, 2007Flood$2.1 million
   National Weather Service narrative

   Following a week of heavy rainfall and a storm event rainfall of nearly five inches, significant flooding occurred in the northern two thirds of Grundy County on August 24th, as runoff worked it's way to ditches and streams that quickly overtopped their banks, followed by flooding along larger streams and the Illinois River. Hundreds of basements filled with water, one rehabiliation center was evacuated in Morris, while a berm was built around the Morris hospital to protect the structure and prevent an evacuation and shutdown of that facility. Local officials used more than 22,000 sandbags in an attempt to protect numerous structures from the rushing water. In other locations,…

8. Aug 4, 2012Thunderstorm Wind$1.5 million
   National Weather Service narrative

   An estimated 40 to 45 trees were blown down in Morris, including some that fell onto houses and cars. A 26 inch diameter tree fell onto a house on Freemont Avenue. A 250 foot transmission tower along I-80 collapsed. A semi-truck parked at a rest stop was toppled.

9. Jul 17, 1996Flash Flood$1.0 million
10. Feb 14, 2015Winter Weather, Grundy$300,000
    National Weather Service narrative

    Winds gusting 40 to 50 mph combined with light snow resulted in white out conditions along a portion of Interstate 55 near Gardner, IL. Between 17 and 22 cars were involved in a pile-up. Twelve people were taken to hospitals, including two people with serious to life threatening injuries. The interstate was shut down for around four hours.

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

109°FJul 14, 1936

All-time low

−26°FDec 28, 1924

Warmest night

81°FJul 27, 1936

Coldest day

−10°FJan 16, 2009

Wettest day

6.51 inSep 28, 2019

Snowiest day

12.0 in2 times, most recently Feb 7, 1933

Hottest year

2024mean 55.1°F

Coldest year

1996mean 45.3°F

Wettest year

201959.06 in

Driest year

195620.28 in

Snowiest season

75.5 in1925-26

Station Morris 1NW (USC00115825), 524 ft elevation, 4.8 miles from the population centre. Daily records from 1912 to October 27, 2026; 97.5% 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 USC00115825.
• 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.
• 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.