Some research recently summarized by personnel at the Raleigh National Weather Service Office indicates that the principle period for violent and potentially deadly tornadoes in our region runs from mid February into early May, with another active period in November. There are often some tornadoes from mid-May into June as well, but there is a notable tendency for these to be of the weak (F0 and F1 category) and short-lived variety that are less likely to do major damage or lead to serious injuries and fatalities.
For the country as a whole, the peak tornado period shifts gradually toward the north and west from late winter into mid-summer. For the southern plains into the middle Mississippi Valley, the primary period for strong tornadoes runs about mid-April into early June, while for the northern plains into the upper midwest the best chance of significant twisters is more like June and July. You can see some very nice animations of how the probability of tornado activity (and some other severe weather events) varies with time across the U.S. at this address:
Copyright 2023 by Capitol Broadcasting Company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.