December 18
- 1957 – On the first day of a major outbreak, strong, fast-moving tornadoes developed across Missouri and Illinois, killing 17 people. An F4 tornado, which closely followed the path of the Tri-State tornado of 1925, killed 11 people in Gorham, Murphysboro, and Sand Ridge, Illinois. Most of the deaths were in a small section of Murphysboro. An F5 tornado completely destroyed Sunfield, Illinois, killing one person and injuring six. Three died in an F2 tornado that hit Chaffee, Missouri. An F4 tornado killed one person in Mount Vernon, Illinois and an F2 tornado killed another person near Knob Lick, Missouri.
- 2018 – a rare EF2 tornado damaged about 250 homes and a strip mall in Port Orchard, Washington. No tornado warning had been issued. No deaths or injuries were reported.