EF1 tornado, Monmouth, Illinois, June 17, 2026

1. EF065 to 85 mph

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. EF186 to 110 mphthis tornado

   Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

3. 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.

4. 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.

5. EF4166 to 200 mph

   Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

6. 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.

7. 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.

Rating, as surveyed

EF1, preliminary

Date

June 17, 2026

Touchdown

8:25 AM CDT (13:25 UTC)

Lifted

8:27 AM CDT (13:27 UTC)

On the ground

2 minutes

Path length

1.3 miles (2.1 km)

Path width

100 yards (91 m)

Deaths

0

Injuries

0

County

Warren County

Touchdown point

40.913, -90.648

Lift-off point

40.898, -90.634

Highest wind the damage implies

100 mph

Surveyed by

NWS DVN

The office's name for it

Monmouth Tornado

Survey last edited

June 18, 2026

Record number

None yet. SPC numbers 2026 in the spring of 2027.

A short-lived EF-1 tornado developed in Monmouth Illinois and tracked southeast through town for 1.3 miles, with estimated maximum winds of 100 mph. Along the tornado path, structural damage was observed in the heart of Monmouth, with a few

buildings seeing roofing damage, many windows blown out, and part of their brick walls damaged. Some houses also saw loss of shingles. Otherwise, a lot of damage was observed to trees along a clear convergent path, with numerous snapped, uprooted, and a lot of trees with downed large branches throughout. Some of these large tree sections were downed on houses as well.

Written by NWS DVN in the NWS Damage Assessment Toolkit. A survey is revised as better evidence arrives.

A strong storm system for mid-June brought two rounds of thunderstorm on Wednesday June 17th. The strongest round of storms occurred during the morning hours that brough damaging winds (some significant), heavy rain, and two EF-1 tornadoes in Illinois which occurred in Monmouth and Warsaw. |Many trees fell and power lines were damaged, along with several reports of flash flooding. There were also 4-5 train cars that were pushed off the railroad just south of Monmouth, IL in Warren County due to significant straight-line winds (estimated near 100 mph). Additional train cars derailed as a result of these cars being blown off.

A short-lived EF-1 tornado developed in Monmouth Illinois and tracked southeast through town for 1.3 miles, with estimated maximum winds of 100 mph. Along the tornado path, structural damage was observed in the heart of Monmouth, with a few buildings seeing roofing damage, many windows blown out, and part of their brick walls damaged. Some houses also saw loss of shingles. Otherwise, a lot of damage was observed to trees along a clear convergent path, with numerous snapped, uprooted, and a lot of trees with downed large branches throughout. Some of these large tree sections were downed on houses as well.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down.

The county was under a severe thunderstorm watch, issued at 09:07 UTC and running to 16:00 UTC.

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 Storm Prediction Center had this point in a Enhanced Risk, with a 0.10 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 12:59 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 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.

Galesburg (GBG), 18 km from the path, in the two hours either side.

From the Iowa Environmental Mesonet's archive of airport observations.

The Quad Cities radar (KDVN), 79 km away, was scanning. The volume nearest the touchdown began at 13:27 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.

Local storm reports within 60 km of the path, in the three hours either side.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

The live radar over the trackEvery 2026 tornado in IllinoisEvery tornado in Illinois since 1950Warnings in force in Illinois nowThe forecast where you are

27 more have been surveyed in the United States that day, so far.

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.

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.