The National Weather Service has extended the severe thunderstorm warning for DeKalb County until 11:30 a.m.
The service has advised people to move to an interior room on the lowest floor of their home or business as these storms can produce winds in excess of 60 miles per hour.
Heavy rains, large hail and deadly lightning are expected. Drivers should avoid roads that are covered in water.
The alert also covers Grundy, Kane, Kendall and LaSalle counties.