According to the Scott Air Force Base, 375th Mission Support Group (Meteorologists), Tornado season in Illinois is from mid-March through June, but tornados have occurred in every month of the year. Illinois averages 44 tornados per year; however, there can always be more. 1974 holds the record for the most tornadoes in a year with 107. Tornados are usually short in duration, are produced during severe thunderstorms, and are most frequently seen from mid-afternoon through the evening. Tornados typically move from southwest toward the northeast at speeds of 30 to 40 mph, but can move as fast as 70 mph and produce wind gusts of up to 300 mph. Not every severe thunderstorm will produce a tornado, but if conditions are right, a tornado can develop in minutes. Tornados can take many forms, but are typically funnel shaped.
Tornado Watch: Conditions are favorable for a tornado to form. Expect heavy rains, hail, and high winds. Keep the radio/television on and listen for the latest weather information.
Tornado Warning: A tornado has been sighted in the area. Surrounding communities will sound their sirens as they see appropriate based on their Doppler readings. Seek Shelter immediately!
Check the emergency plan in your building, office or classroom to locate areas of refuge in the event of a tornado.