We introduce a novel method for the spatial–temporal cluster analysis of severe tornado touchdowns that are part of tornado outbreaks. Tornado outbreaks, groups of tornadoes occurring close to each other in time and space, constitute a severe hazard that has few quantitative measures. Our new approach, which we illustrate using three USA severe tornado outbreaks and models, differentiates between types of tornado outbreaks and, within outbreaks, identifies clusters in both time and space.