Weather statistics show it’s not unheard of for a tornado to touch down in Illinois during November.
Illinois State Climatologist Jim Angel studied the years 1950 to 2010 and found nearly 70 tornadoes occurred in November, which is more than October or December.
He said what made Sunday different was the number of tornadoes.
“All our other outbreaks tend to happen in the springtime. So the ones in November tend to be single events, but this is by far the biggest number that we've seen in November,” Angel said.
Angel said the state has seen more “cold weather” tornadoes in recent years. One example is the February 2012 storm in Harrisburg that killed eight people.
The Harrisburg storm was classified as an EF-4 tornado, whichis the second most powerful.
Two of the tornadoes this past weekend were also EF-4. Those are rare in the state, but weather statistics show they have accounted for the most deaths.
Sunday’s tornadoes in Illinois killed six people.