TL;DR

Six tornadoes were reported across Illinois and Wisconsin on Monday afternoon and evening, July 27, 2026. The National Weather Service confirmed concentrated tree and structural damage in Glen Ellyn, Illinois, and survey teams are still working to determine the full extent of the Appleton, Wisconsin tornado. No fatalities have been reported. The outbreak was part of a broader severe weather event that produced 109 hail reports and 310 wind reports across 24 states.

A multi-state severe weather event on Monday, July 27, 2026, produced six confirmed tornadoes across Illinois and Wisconsin, along with widespread damaging winds and large hail across the Upper Midwest and Great Lakes. The tornado reports spanned a nine-hour window from mid-afternoon through late evening, with the most significant damage concentrated in suburban Chicago and northeastern Wisconsin.

Where the tornadoes touched down

The National Weather Service received six tornado reports on Monday:

  • 1654 UTC (11:54 AM CDT) — Glen Ellyn, Illinois: Concentrated tree damage on Stacy Court in North Glen Ellyn, including large trees snapped and uprooted, some onto homes.
  • 1655 UTC (11:55 AM CDT) — Glen Ellyn, Illinois: Photographic confirmation of a tornado near the location of a radar-indicated tornadic debris signature.
  • 1656 UTC (11:56 AM CDT) — Appleton, Wisconsin: Preliminary tornado start location and time confirmed by NWS Green Bay. Survey ongoing.
  • 1751 UTC (12:51 PM CDT) — Markham, Illinois: Concentrated tree and structural damage on the 2300 block of West 167th Street, within a likely tornado path.
  • 1759 UTC (12:59 PM CDT) — Hazel Crest, Illinois: Concentrated tree damage along westbound I-80/I-294 at the Dixie Highway exit, likely part of the Markham tornado path.
  • 2314 UTC (6:14 PM CDT) — Hoopeston, Illinois: Video evidence from storm spotters showed a brief touchdown one mile west of IL-1 and about 100 yards south of Thompson Street. A power pole and a street sign were damaged.

All six tornadoes are currently rated UNK (unknown) pending completion of National Weather Service damage surveys. EF-scale ratings are typically released within 24 to 72 hours of an event.

The Glen Ellyn and suburban Chicago tornadoes

The most significant damage occurred in the Glen Ellyn area of DuPage County, Illinois, where NWS Chicago (LOT) documented "concentrated tree damage" with large trees snapped and uprooted onto homes. The damage pattern aligns with a tornadic debris signature detected by radar at the time.

A second tornado touched down roughly an hour later in Markham, Illinois, about 25 miles southeast of Glen Ellyn, producing structural damage on West 167th Street. The NWS noted that concentrated tree damage extended along Interstate 80 and Interstate 294 near the Dixie Highway exit in neighboring Hazel Crest, suggesting the tornado tracked through multiple communities.

The timing of the Glen Ellyn tornado—late morning on a weekday—likely reduced the number of people outdoors and in vehicles.

Appleton tornado survey underway

NWS Green Bay confirmed a preliminary tornado touchdown two miles west-northwest of Appleton, Wisconsin, at 1656 UTC (11:56 AM CDT). The office noted that a survey is ongoing, but no additional details on the damage path, width, or intensity have been released.

Appleton, a city of roughly 75,000 in the Fox Cities metro area, has a documented tornado history. The most recent significant event was an EF1 tornado in August 2021 that caused damage to homes and businesses in the northern part of the city.

Late-evening tornado in Hoopeston

The final tornado of the day touched down just before sunset in Hoopeston, Illinois, a small city in Vermilion County. Storm spotters captured video of the brief touchdown, which damaged a power pole and a street sign. The NWS Springfield office (ILX) noted the tornado occurred one mile west of Illinois Route 1 and about 100 yards south of Thompson Street.

Hoopeston is located in Vermilion County, an area that sees occasional tornado activity during the summer months when shortwave troughs and frontal boundaries interact with warm, moist air from the Gulf of Mexico.

Broader severe weather context

Monday's tornadoes were embedded within a much larger severe weather outbreak. The NOAA Storm Prediction Center logged 109 hail reports and 310 wind reports across 24 states, stretching from Alabama and Georgia in the Southeast to Wisconsin and Michigan in the Great Lakes, and west to South Dakota, Colorado, and New Mexico.

The most significant hail report came from northwest of Gresham, Wisconsin, where a social media image confirmed grapefruit-size hail (4.5 inches in diameter) at 1528 UTC. Multiple reports of baseball- and tennis-ball-size hail were received across northeastern Wisconsin, including a 3-inch report from Algoma.

Damaging wind reports were widespread, with trees and power lines downed across Alabama, Kentucky, Wisconsin, Illinois, and Michigan. A home weather station in North Prairie, Wisconsin, measured a 62 mph wind gust at 1533 UTC.

What drove the outbreak

The severe weather was driven by a cold front sweeping east-southeastward across the Great Lakes and Midwest, interacting with a moist, unstable air mass. Upper-level winds of 45 to 55 knots provided strong wind shear, supporting both supercells and organized line segments capable of producing tornadoes, large hail, and damaging straight-line winds.

The Storm Prediction Center's Day 1 outlook issued Monday morning highlighted the potential for severe thunderstorms across the region, noting "ample deep-layer shear and moderate low-level shear" that would support rotating storms.

Tornado safety during the day

Monday's tornadoes occurred during daylight hours, which generally improves warning response and survival rates compared to nocturnal events. Tornadoes that strike at night are more than twice as likely to result in fatalities, largely because people are asleep and less likely to receive warnings.

During the day, visual confirmation—either by spotters or the public—can supplement radar detection and provide critical ground truth for warning decisions. In Glen Ellyn, photographic evidence of the tornado was relayed to the National Weather Service within minutes of the touchdown, helping confirm the threat.

Wireless Emergency Alerts (WEA) for tornado warnings are broadcast directly to mobile phones in the warned area and bypass Do Not Disturb mode on most devices. Third-party weather apps, however, are silenced by Do Not Disturb unless users manually configure notification settings. For users who want an additional layer of alerting—particularly for warnings issued at night—services like VORTEX Pro can place phone calls that ring through Do Not Disturb when Emergency Bypass is enabled for the number.

What's next

National Weather Service survey teams will continue assessing damage in Glen Ellyn, Markham, Hazel Crest, Appleton, and Hoopeston over the coming days. EF-scale ratings, path lengths, and maximum path widths will be published in follow-up reports.

VORTEX is a free web app at vortexintel.app that monitors severe weather nationwide. Pro ($4.99/month) places phone calls to your phone when a tornado or flash flood warning is issued for a location you care about — calls can ring through Do Not Disturb once you enable Emergency Bypass for the number, unlike most third-party app notifications.