Tornadoes · United States · Illinois · 2026
EF1 tornado, Will County, Illinois, August 11, 2026
This EF1 tornado ran 7.6 miles across Will County on August 11, 2026, touching down at 10:39 AM CDT and reaching 200 yards wide. It killed nobody.
Preliminary. This is NWS LOT's damage survey, filed in the Damage Assessment Toolkit as Mokena - Tinley Park. The rating, the path and the casualties are the survey's and can change while it is revised. The Storm Prediction Center compiles the official record of 2026 from these surveys and publishes it in the spring of 2027; this page moves to that tornado's permanent address when it does.
The rating scale
Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.
EF065 to 85 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mphthis tornado
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
EF2111 to 135 mph
Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.
EF3136 to 165 mph
Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
EF5over 200 mph
Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.
Unrated
The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.
The survey
- Rating, as surveyed
- EF1, preliminary
- Date
- August 11, 2026
- Touchdown
- 10:39 AM CDT (15:39 UTC)
- Lifted
- 10:46 AM CDT (15:46 UTC)
- On the ground
- 7 minutes
- Path length
- 7.6 miles (12.2 km)
- Path width
- 200 yards (183 m)
- Deaths
- 0
- Injuries
- 0
- County
- Will County
- Touchdown point
- 41.549, -87.959
- Lift-off point
- 41.534, -87.817
- Highest wind the damage implies
- 95 mph
- Surveyed by
- NWS LOT
- The office's name for it
- Mokena - Tinley Park
- Survey last edited
- August 25, 2026
- Record number
- None yet. SPC numbers 2026 in the spring of 2027.
What the survey found
This tornado began near the intersection of W. Maple Road and Blodgett Road and then crossed I-80 near mile marker 141. The tornado continued in a southeasterly direction, causing mainly minor tree damage as it roughly paralleled W Regan Road and 195th Street. The tornado reached its peak intensity in a subdivision near St. Mary's Catholic Church, where several residences sustained shingle and soffit damage and large hardwood trees were snapped, consistent with peak winds of 85 to 95 mph. The tornado then continued east roughly along 195th Street before lifting just north of the Hilda Walker Intermediate School.
Written by NWS LOT in the NWS Damage Assessment Toolkit. A survey is revised as better evidence arrives.
The damage survey
324 damage points were recorded along this path by NWS LOT, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EFU. The highest wind the damage implies is 110 mph.
- Industrial sign blown down to the east.
- Chicago Heights reports power lines downed onto road near Ashland Avenue and 16th Street.
- Photo shared via social media shows sections of north facing wall blown out or collapsed from second floor room. Large sections of siding removed from remainder of building. Exact damage indicator difficult to determine, and nearby damage appears less severe in photo. Wind speed very approximately estimated.
- Numerous fence panels blown down. Tree branches downed. Church steeple bent. Damage direction to the east.
Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.
The warnings
29 minutes of warning. NWS LOT issued a tornado warning for this county at 15:10 UTC, 29 minutes before the tornado touched down, in force until 16:00 UTC.
The county was under a severe thunderstorm watch, issued at 12:39 UTC and running to 16:38 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 23:22 UTC | 00:37 UTC | Severe Thunderstorm Watch | LOT |
| 12:39 UTC | 16:38 UTC | Severe Thunderstorm Watch | LOT |
| 15:10 UTC | 16:00 UTC | Tornado Warning | LOT |
| 15:17 UTC | 16:15 UTC | Severe Thunderstorm Warning | LOT |
| 15:20 UTC | 16:15 UTC | Severe Thunderstorm Warning | LOT |
| 15:27 UTC | 16:04 UTC | Tornado Warning | LOT |
| 15:36 UTC | 18:30 UTC | Flood Advisory | LOT |
| 15:36 UTC | 15:53 UTC | Tornado Warning | LOT |
| 15:49 UTC | 16:25 UTC | Severe Thunderstorm Warning | LOT |
Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.
The forecast that day
The Storm Prediction Center had this point in a Enhanced Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 12:26 UTC.
SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.
The air that afternoon
The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.
Lincoln, IL (KILX), 12:00Z
3.7 hours before the tornado, 166 km from the path. August 11, 2026.
- Mixed-layer CAPE
- 2617 J/kg
- Mixed-layer CIN
- -144 J/kg
- Surface CAPE
- 3287 J/kg
- Mixed-layer LCL
- 1547 m above ground
- 0-6 km bulk shear
- 20 kt
- 0-1 km bulk shear
- 28 kt
- 0-1 km storm-relative helicity
- 142 m²/s²
- 0-3 km storm-relative helicity
- 140 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 4.5
- 0-3 km lapse rate
- 4.7 K/km
Lincoln, IL (KILX), 00:00Z
8.3 hours after it, 166 km from the path. August 12, 2026.
- Mixed-layer CAPE
- 4020 J/kg
- Mixed-layer CIN
- -54 J/kg
- Surface CAPE
- 4858 J/kg
- Mixed-layer LCL
- 1243 m above ground
- 0-6 km bulk shear
- 42 kt
- 0-1 km bulk shear
- 13 kt
- 0-1 km storm-relative helicity
- 81 m²/s²
- 0-3 km storm-relative helicity
- 147 m²/s²
- Significant tornado parameter
- 2.0
- Supercell composite
- 15.0
- 0-3 km lapse rate
- 7.2 K/km
The radar
The Chicago radar (KLOT), 18 km away, was scanning. The volume nearest the touchdown began at 15:41 UTC.
Open the radar archive at this moment, over the track
Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.
What was reported nearby
Local storm reports within 60 km of the path, in the three hours either side.
| Time (UTC) | Report | Where | County | Remark |
|---|---|---|---|---|
| 15:03 UTC | TSTM WND DMG | 1 Nne Sandwich | De Kalb, IL | Two approx 8 inch diameter branches down on pleasant street. |
| 15:03 UTC | TSTM WND DMG | 1 Nne Sandwich | De Kalb, IL | Two approx 8 inch diameter branches down on pleasant street. |
| 15:03 UTC | TSTM WND DMG | 1 Nne Sandwich | De Kalb, IL | Two approx 8 inch diameter branches down on pleasant street. |
| 15:07 UTC | TSTM WND DMG | 1 Ese Big Rock | Kane, IL | Photo on social media showed a tree 12 to 18 inches in diameter snapped and fell onto a fence in a subdivision near Garnart Road. |
| 15:07 UTC | TSTM WND DMG | 1 Ese Big Rock | Kane, IL | Photo on social media showed a tree 12 to 18 inches in diameter snapped and fell onto a fence in a subdivision near Garnart Road. |
| 15:07 UTC | TSTM WND DMG | 1 Ese Big Rock | Kane, IL | Photo on social media showed a tree 12 to 18 inches in diameter snapped and fell onto a fence in a subdivision near Garnart Road. |
| 15:11 UTC | TSTM WND GST 70 | Sugar Grove | Kane, IL | Significant tree damage reported in town. |
| 15:11 UTC | TSTM WND GST 70 | Sugar Grove | Kane, IL | Significant tree damage reported in town. |
| 15:11 UTC | TSTM WND GST 85 | 2 Wnw Sugar Grove | Kane, IL | KARR - Aurora / Sugar Grove Airport. |
| 15:11 UTC | TSTM WND GST 85 | 2 Wnw Sugar Grove | Kane, IL | KARR - Aurora / Sugar Grove Airport. |
| 15:12 UTC | TSTM WND DMG | 1 Nnw Sugar Grove | Kane, IL | Photo on social media showed a large tree blown down partially blocking a residential road near Galena Boulevard and Route 47. |
| 15:12 UTC | TSTM WND DMG | 1 Nnw Sugar Grove | Kane, IL | Photo on social media showed a large tree blown down partially blocking a residential road near Galena Boulevard and Route 47. |
| 15:12 UTC | TSTM WND DMG | 1 Nnw Sugar Grove | Kane, IL | Photo on social media showed a large tree blown down partially blocking a residential road near Galena Boulevard and Route 47. |
| 15:13 UTC | TSTM WND DMG | 1 Ne Yorkville | Kendall, IL | Photo shared of a large tree down. Time estimated by radar. |
| 15:13 UTC | TSTM WND DMG | 1 Ne Yorkville | Kendall, IL | Photo shared of a large tree down. Time estimated by radar. |
| 15:13 UTC | TSTM WND DMG | 1 Ne Yorkville | Kendall, IL | Photo shared of a large tree down. Time estimated by radar. |
| 15:13 UTC | TSTM WND GST 97 | 1 Se Sugar Grove | Kane, IL | Home weather station measured a 97 mph wind gust. |
| 15:13 UTC | TSTM WND GST 97 | 1 Se Sugar Grove | Kane, IL | Home weather station measured a 97 mph wind gust. |
| 15:13 UTC | TSTM WND GST 97 | 1 Se Sugar Grove | Kane, IL | Home weather station measured a 97 mph wind gust. |
| 15:14 UTC | TORNADO | 2 W Oswego | Kendall, IL | NWS survey confirms an EF-0 tornado with peak winds near 75 mph, peak width of 150 yards, and path length of 5.2 miles. |
| 15:14 UTC | TORNADO | 2 W Oswego | Kendall, IL | NWS survey confirms an EF-0 tornado with peak winds near 75 mph, peak width of 150 yards, and path length of 5.2 miles. |
| 15:14 UTC | TORNADO | 2 W Oswego | Kendall, IL | NWS survey confirms an EF-0 tornado with peak winds near 75 mph, peak width of 150 yards, and path length of 5.2 miles. |
| 15:15 UTC | TSTM WND DMG | 1 N Seneca | La Salle, IL | Photo on social media showed a large tree limb snapped off a tree near Main Street and Jackson Street. |
| 15:15 UTC | TSTM WND DMG | 1 N Seneca | La Salle, IL | Photo on social media showed a large tree limb snapped off a tree near Main Street and Jackson Street. |
| 15:15 UTC | TSTM WND DMG | 1 N Seneca | La Salle, IL | Photo on social media showed a large tree limb snapped off a tree near Main Street and Jackson Street. |
| 15:16 UTC | TSTM WND DMG | 1 N Boulder Hill | Kendall, IL | multiple large branches 6-8 inches in diameter down north side of town. |
| 15:16 UTC | TSTM WND DMG | 1 N Boulder Hill | Kendall, IL | multiple large branches 6-8 inches in diameter down north side of town. |
| 15:16 UTC | TSTM WND DMG | 1 N Boulder Hill | Kendall, IL | multiple large branches 6-8 inches in diameter down north side of town. |
| 15:18 UTC | TSTM WND DMG | 1 Nnw Oswego | Kendall, IL | tree branches reported down. |
| 15:18 UTC | TSTM WND DMG | 1 Nnw Oswego | Kendall, IL | tree branches reported down. |
| 15:18 UTC | TSTM WND DMG | 1 Nnw Oswego | Kendall, IL | tree branches reported down. |
| 15:18 UTC | TSTM WND GST 64 | 2 Se Yorkville | Kendall, IL | |
| 15:18 UTC | TSTM WND GST 64 | 2 Se Yorkville | Kendall, IL | |
| 15:19 UTC | TSTM WND GST 60 | 1 Se Seneca | La Salle, IL | Private weather station. |
| 15:19 UTC | TSTM WND GST 60 | 1 Se Seneca | La Salle, IL | Private weather station. |
| 15:20 UTC | TORNADO | 5 E Seneca | Grundy, IL | An NWS storm survey confirmed that an EF-0 tornado with estimated peak winds of 80 mph, a path length of 1.6 miles, and a peak width of 250 yards occurred in Norman Township, southwest of Morris. |
| 15:21 UTC | TSTM WND DMG | 4 Wnw Batavia | Kane, IL | Photos of snapped tree branches. Time estimated by radar. |
| 15:21 UTC | TSTM WND DMG | 4 Wnw Batavia | Kane, IL | Photos of snapped tree branches. Time estimated by radar. |
| 15:21 UTC | TSTM WND DMG | 4 Wnw Batavia | Kane, IL | Photos of snapped tree branches. Time estimated by radar. |
| 15:21 UTC | TSTM WND GST 65 | 1 Ene Oswego | Kendall, IL | Private weather station: 0.9 SSE Oswego. |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2026 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are
The other tornadoes of August 11, 2026
28 more have been surveyed in the United States that day, so far.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| August 11 | 7:58 AM EDT | EF0 | Jay, IN | 0.6 | 15 | |||
| August 11 | 7:31 AM CDT | EF1 | Delaware, IA | 2.4 | 150 | |||
| August 11 | 7:44 AM CDT | EF1 | Delaware, IA | 1.5 | 100 | |||
| August 11 | 7:45 AM CDT | EF1 | Delaware, IA | 2.6 | 75 | |||
| August 11 | 9:24 AM EDT | EF0 | Clark, OH | 4.5 | 150 | |||
| August 11 | 8:29 AM CDT | EF0 | Clinton, IA | 0.3 | 50 | |||
| August 11 | 9:30 AM EDT | EF1 | Champaign, OH | 3.6 | 200 | |||
| August 11 | 9:31 AM EDT | EF1 | Clark, OH | 9.2 | 200 | |||
| August 11 | 9:33 AM EDT | EF2 | Clark, OH | 3.5 | 400 | |||
| August 11 | 9:44 AM EDT | EF1 | Madison, OH | 0.8 | 125 | |||
| August 11 | 9:51 AM EDT | EF0 | Madison, OH | 1.2 | 100 | |||
| August 11 | 10:05 AM EDT | EF0 | Franklin, OH | 2.7 | 150 | 2 | ||
| August 11 | 10:05 AM EDT | EF1 | Franklin, OH | 1.8 | 100 | |||
| August 11 | 10:08 AM EDT | EF1 | Franklin, OH | 1.3 | 150 | |||
| August 11 | 10:14 AM CDT | EF0 | Kendall, IL | 5.4 | 150 | |||
| August 11 | 10:20 AM CDT | EF0 | Grundy, IL | 1.6 | 250 | |||
| August 11 | 10:23 AM CDT | EF0 | Grundy, IL | 2.2 | 150 | |||
| August 11 | 10:37 AM CDT | EF1 | Will, IL | 1.5 | 150 | |||
| August 11 | 10:41 AM CDT | EF1 | Cook, IL to IN | 22.5 | 300 | |||
| August 11 | 10:43 AM CDT | EF2 | Will, IL to IN | 26.2 | 500 | |||
| August 11 | 10:55 AM CDT | EF1 | Cook, IL | 3.3 | 300 | |||
| August 11 | 3:13 PM EDT | EF1 | Butler, OH | 11.3 | 500 | |||
| August 11 | 3:47 PM EDT | EF0 | Clermont, OH | 5.2 | 200 | |||
| August 11 | 3:49 PM EDT | EF0 | Clermont, OH | 5.5 | 150 | |||
| August 11 | 3:51 PM EDT | EF0 | Boone, KY | 2.9 | 150 | |||
| August 11 | 3:56 PM EDT | EF0 | Brown, OH | 6.4 | 200 | |||
| August 11 | 3:12 PM CDT | EF1 | Piatt, IL | 22.5 | 800 | |||
| August 11 | 4:16 PM EDT | EF1 | Brown, OH | 7.1 | 350 |
What this means
Ratings are the survey's, read off the damage rather than measured; the rating scale is above. A survey can be revised, so the rating, the path and the casualties can all still change.
Sources
NWS Damage Assessment Toolkit, the record the survey teams file from the damage, and NOAA Storm Prediction Center storm reports. Neither is the official database for 2026, which SPC publishes in the spring of 2027.