NOAA's National Centers for Environmental Information
Visit:NCEI U.S. Tornadoes
June 2021 Tornado Occurrences
Source: SPC
According to data from NOAA's Storm Prediction Center, during June, there were 109 preliminary tornado reports. This is well below the 1991-2010 average of 243 tornadoes for the month of June. Historically, the month of June represents the second-highest average number of tornadoes based on the 1991-2010 reference period. This June was a relatively inactive month for tornadoes with only 3 June days having 10 or more confirmed tornadoes across the United States. Yet, there were still several multi-day periods that produced dozens of tornado and associated impacts. The days with the highest count of tornadoes and their impacts are noted below in chronological order.
On June 7-8, there were 17 tornadoes that impacted North Dakota, South Dakota, Colorado, Texas, Arkansas and Indiana. Many of these tornadoes were focused in southeastern South Dakota and southwestern Indiana. These were tornadoes that mostly occurred over rural areas, which limited their impact. These were all weaker EF-1, EF-0 or EF-U tornadoes that caused mostly minor damage to farmsteads, homes and other infrastructure. There was at least 1 injury and no reported fatalities.
During June 18-20, there were 37 tornadoes that impacted Colorado, Nebraska, Iowa, Illinois, Indiana, Ohio and Michigan producing at least 11 injuries in Illinois. There were also several tornadoes in Mississippi, Alabama and Georgia. One of the more impactful tornadoes was a EF-2 in southern Alabama that caused at least 20 injuries along a 22 mile path. In addition, a destructive EF-3 tornado tore across the Chicago suburbs heavily damaging or destroying homes in Woodridge, Naperville and Darien. There were also other EF-2 and EF-1 tornadoes causing damage to homes, businesses, vehicles and infrastructure. There were several additional tornado-related injuries but no fatalities.
On June 24-26, there were 26 tornadoes that impacted Iowa, Missouri, Illinois, Indiana, Wisconsin and Michigan. These were mostly weaker EF-1 and EF-0 tornadoes that caused mostly minor damage to farmsteads, homes and other infrastructure. There was one EF-2 tornado that tracked near Fort Austin, Michigan where it entered Lake Huron. Several homes were heavily damaged in addition to damage to vehicles and infrastructure. There were at least 6 tornado-related injuries but no fatalities.
Did You Know?
Tornado Count
Final monthly tornado counts are typically less than the preliminary count. This can be due to some phenomena being inaccurately reported as tornadic activity or a single tornado being reported multiple times. Tornado accounts are reported to the local National Weather Service forecast offices who are responsible for going into the field and verifying each tornado reported. This process often takes several months to complete. Once all reports have been investigated, the final count is published by the Storm Prediction Center (SPC).
The Tornado Monthly Climate Reports are written using the preliminary numbers because the final data is not available at the time of production. Historically, for every 100 preliminary tornado reports, at least 65 tornadoes are confirmed. An error bar is depicted on the tornado count graphic representing this uncertainty in the preliminary tornado count.
The following U.S. studies performed by SPC meteorologists offer deeper context and discussion regarding the frequency and distribution of tornado intensity climatologies:
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Edwards, R., H. E. Brooks, and H. Cohn, 2021: Changes in tornado climatology accompanying the Enhanced
Fujita scale. J. Appl. Meteor. Climatol., 60, 1465-1482
DOI: 10.1175/JAMC-D-21-0058.1. - Mccarthy, Daniel & Schaefer, Joseph. (2004). Tornado trends over the past thirty years. paper presented at 14th Conference on Applied Meteorology.