Confirmed, verified tornadoes struck Minnesota on three separate dates during October of 2021: October 9th, 10th, and 13th. This is the greatest known number of October or later tornado dates to have occurred in Minnesota in any year since 1950. Both 1996 and 1973 produced two separate October tornado dates.
It's not unheard of to have tornadoes strike Minnesota deep into our autumn season; in fact, they have been reported in Minnesota as late as November 16 (in 1931). Other November tornadoes affected Minnesota on November 1, 2000, and as recently as November 10, 2012.
According to data maintained by the NOAA Storm Prediction Center, October tornadoes have occurred on 16 different dates from 1950 through 2021 (including the three dates from October 2021). Adding in the two November tornado dates since 1950, that gives us 18 total October or November tornado dates since 1950. Although these mid-autumn tornadoes do not follow any identifiable rhythm, they have an average recurrence of four years. In other words, Minnesota sees tornadoes in October or November about once every four years, on average.
Tornadoes by definition are dangerous, and they tend to damage things they encounter. In that sense, the October 2021 tornadoes were not particularly unusual. The most significant late-season tornadoes on record occurred during an outbreak on October 26, 1996, when 14 separate tornadoes struck portions of central and western Minnesota, producing heavy damage and even minor injuries.
What sets the October of 2021 tornadoes apart is how many different times they occurred. 2021 was not a particularly active or noteworthy tornado season in Minnesota, but it currently stands as the record-holder for most tornado dates to occur after September.
Modified November 30, 2021.