Tennis-Ball Sized Hail, Tornadoes Possible in Illinois and Wisconsin

UPDATED: Thursday, May 15, 2025 at 3:10 pm

The National Weather Service has issued a TORNADO WATCH until 10 pm Thursday (5/15) for Winnebago, Boone, McHenry, Stephenson, and Jo Daviess County.

In the Rockford region and around Chicagoland, Thursday afternoon (5/15) will be the hottest day of the year so far, followed by destructive hail and possible tornadoes.

The Weather Channel is forecasting a high temperature for Rockford in the lower 90s on Thursday, with a significant threat of afternoon thunderstorms after 4 pm.

READ MORE: All U.S. Flags in Illinois Will Be at Half-Staff on Thursday (5/15)

A Hazardous Weather Outlook issued by the National Weather Service (NWS) is forecasting large hail, damaging winds, and isolated tornadoes for the Rockford and Chicago area, with Wisconsin also in the bullseye for dangerous tornadoes.

Record Heat Fuels Storm Development

High temperatures are pushing up into the 90s for the Rockford area and some Chicago suburbs on Thursday (5/15), and with these unusually warm temperatures, dangerous thunderstorms are possible.

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According to the NWS, there's a possibility of large to very large hail with these storms, along with isolated tornadoes.

Elevated to Critical Fire Danger

Besides the threat of severe weather, there's an elevated to critical risk for Fire Danger on Thursday afternoon and Friday (5/16).

With strong southwest winds, warm temperatures, and dry conditions, there's an elevated risk of wildfires. Residents should use extreme caution with any activity that could ignite fires, and keep their radios for fire weather warnings.

Preparedness and Safety Measures

Residents are encouraged to start preparing for severe weather and fire danger, and make sure to have multiple ways to get weather updates on the radio or through our mobile app.

With the threat of high winds, make sure to secure all outdoor objects that can become projectiles, and have an emergency kit always handy.

We'll be updating the latest weather forecast information on Thursday afternoon, so check back frequently.