Winnebago County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Winnebago 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. Sep 4, 2006Flash Flood$20.0 million
   National Weather Service narrative

   Thunderstorms developed over southeast Winnebago County and eastern parts of the City of Rockford during the afternoon and evening of September 4th. The thunderstorms continued to redevelop over the same areas, as they pushed north and weakened. Some areas across parts of eastern Rockford received heavy rain for two to three hours. As a result, massive and severe flooding occured. Most of the flooding occurred in and around the Keith Creek Watershed. Some of the damage included a large section of a concrete drainage ditch that was washed out on Harrison Avenue near 20th Street. Hundreds of basements were flooded. Fifteen of these basements suffered structural damage and were…

2. Jun 10, 2008Flood$6.0 million
   National Weather Service narrative

   Area streams were already running above normal due to heavy runoff from a wet winter and spring. Additional heavy rain in June cause moderate to major flooding of rivers. June rainfall amounts included 8.87 inches at Shirland, 6.16 inches in Roscoe, and 6.27 inches at Rockford. Even heavier rain, in excess of 10 inches, fell in southern Wisconsin. By June 10 the Rock River at Rockton reached moderate flood stage of 11 feet. It crested at 14.72 feet on the 18th. This was the second highest crest on record. Downstream the river crested at 14.23 feet at Latham Park. The moderate to major flooding continued through the end of June and into July. The Pecotonica River at Shirland…

3. Jul 5, 2003Thunderstorm Wind$5.0 million
   National Weather Service narrative

   A long lived line of severe thunderstorms, known as a derecho, moved from Iowa into northern Illinois early in the morning of Saturday July 5. The storm caused widespread damage to trees and power lines in Ogle county. The most intense damage occurred in Winnebago county, as the storm cut a wide swath from Pecatonica to the west side of Rockford, through downtown Rockford, to the southeast side of the city and Cherry Valley. Near Pecatonica corn was flattened and trees were damaged. In Rockford, many large trees were uprooted or snapped. Many limbs and power lines were down. 80,000 customers were without power. A 731 foot TV tower and antenna was blown down by the wind near…

4. Jul 13, 2024Flash Flood$2.0 million
   National Weather Service narrative

   Thunderstorms producing torrential rainfall moved across southern Winnebago County and Rockford during the late evening of July 13th into the early morning of July 14th producing significant flash flooding and numerous water rescues, though no injuries were reported.||Water rescues were reported near Eastmoreland Avenue and Broadway; Near Auburn Street and Huffman Boulevard; Broadway at Woodruff Avenue; Near Charles Street and 22nd Street; Green Dale Drive and Ashbrook Drive; Spring Creek Road and North 2nd Street; Riverside Boulevard and Latham Street; Near Chelsea Avenue and Arden Court; Near State Street and Trainer Road; At Don Carter Lanes on Street State; Auburn Street and…

5. Aug 7, 2007Flood$2.0 million
   National Weather Service narrative

   Flooding continued from heavy rains and flash flooding earlier on August 7th. In Rockford, multiple roads closed due to flooding inlcuding Valencia, Avalon, and Churchill Grove from 9th to 20th. City officials in Rockford feared that water flowing over the spillway at the Alpine dam in Rockford would result in structural failure of the 65 year old dam. Residents in a 1200 home area immediately downstream of the dam along Keith Creek were evacuated as a precaution. Flood waters up to the first level of some houses and as many as 12 basement collapses were reported as a result of the flooding. Water came within 2 feet of flowing over the Alpine dam spillway at around 1130 AM. Severe…

6. Aug 7, 2007Flash Flood$1.0 million
   National Weather Service narrative

   Over 6 inches of rain fell over southeast Rockford in a three hour period. The runoff quickly overwhelmed Keith and Madigan Creeks in Rockford as well as other streams across eastern Winnebago County. Hardest hit areas included the Keith Creek watershed in southeast Rockford, the same area that experienced flash flooding on Labor Day 2006. Twenty intersections flooded in Rockford with six cars stranded in flood waters. Illinois Central railroad tracks washed out at Malford Road just south of Harrison.

7. Jul 24, 2010Flash Flood$632,000
   National Weather Service narrative

   Very heavy rain fell across Winnebago County producing widespread flooding and flash flooding, including creek and river flooding. Significant flooding was reported near Keith Creek in the Churchill Park area on the east side of Rockford. Route 2 was flooded and impassible near South Beloit Road.

8. Jul 14, 2024Flash Flood$500,000
   National Weather Service narrative

   Thunderstorms producing torrential rainfall moved across southern Winnebago County and Rockford during the evening of July 14th producing significant flash flooding. Street flooding with stalled vehicles were reported all across Rockford. Multiple cars were flooded along roadways near the Alpine Dam where water levels reached two feet below the spillway. Widespread street flooding was reported near Gorham Place and Barrington Road and also near 11th Street and Broadway Street. Significant erosion occurred near roadways and parking lots at the Swedish American Hospital on State Street. Numerous basements were flooded.

9. Nov 22, 2010Tornado$500,000
   National Weather Service narrative

   Based on an eyewitness report, a tornado touched down in the backyard of a home just west of Interstate 39, on the eastern edge of a subdivision. The tornado then blew over a school bus near the intersection of Argyle and Harlem Roads. There were six people on the bus, the driver and five children. All six people were taken to the hospital but none of the injuries were serious. The tornado then knocked down eleven electrical high tension towers just southwest of the same intersection. The tornado was likely at EF2 intensity at this time and as it crossed into Boone County.

10. Jun 28, 2017Flash Flood$500,000
    National Weather Service narrative

    Very heavy rain fell across Winnebago County during the evening hours of June 28th. Numerous roads were flooded, closed and impassable due to flash flooding. In Rockford, numerous cars were stranded in flood waters with several water rescues from the stranded vehicles. Kent Creek was out of its banks. A parking lot at a pharmacy was flooded and people were unable to leave the building. Numerous residential roads were flooded and impassable in Loves Park, Machesney Park and Pecatonica. In Winnebago, 4 to 6 inches of flowing water was reported on roads. Storm total rainfall totals included 5.69 inches in Loves Park; 5.48 inches at Rockford International Golf Course; 5.21 inches at…

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

105°FJul 7, 2012

All-time low

−31°FJan 31, 2019

Warmest night

80°FJul 19, 2019

Coldest day

−14°FJan 18, 1994

Wettest day

5.70 inAug 14, 1987

Snowiest day

11.7 inNov 25, 2018

Hottest year

2012mean 53.2°F

Coldest year

1979mean 45.4°F

Wettest year

197356.48 in

Driest year

197623.25 in

Snowiest season

74.5 in1978-79

Station Rockford Gtr Rockford Airport (USW00094822), 725 ft elevation, 8.1 miles from the population centre. Daily records from 1951 to October 26, 2026; 100.0% 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 USW00094822.
• 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.