Billion-dollar disaster numbers have increased since 1980. The annual average is 6.3 events, but the annual average for the last 5 years is at 12.6 disasters.
Dr. Harold Brooks with the National Severe Storms Laboratory has noticed an increase in the number of tornado outbreaks in the United States. He shared this information through a Climate Central webinar this summer.
Since 1970 the average number of outbreaks has increased from one to four a year. For the study, a tornado outbreak is categorized as one day with at least 25 or more EF-1 or greater tornadoes.