Most tornado damage paths are less than 100 yards wide and a couple of miles long, but can be as much as a mile wide and 50 miles long.
Most tornadoes occur in the spring, but have occurred every month of the year.
Most tornadoes produce winds 60 to 120 mph. The most violent tornadoes can produce winds up to 318 mph. There is an average of 29 tornadoes per year in Illinois. Illinois led all other states in 1998 in the number of tornadoes. Thunderstorms can produce strong winds, lightning, hail or heavy rain.