• 1968: A blizzard visited South Dakota and Minnesota on the 21st and 22nd. Snowfall during the snowstorm was generally 1 to 2 inches in the western part of South Dakota, to 5 to 10 inches in Minnesota, with more than 12 inches in an area from Artichoke Lake in Big Stone County to the southeast in Minnesota, and up to 18 inches in east central and southeast South Dakota. The snowfall, on top of an already-existing 10-inch layer of powdery snow, was whipped by 30-50 mph winds, with some winds over 50 mph in Minnesota, that occasionally reduced visibility to near zero, created snow drifts up to 10 feet or more, stopped almost all forms of traffic, blocked many primary highways for most of Sunday the 22nd, and blocked most of the secondary roads as well as some other roads for nearly a week.
• Due to good blizzard warnings and the fact that the blizzard occurred late Saturday through Sunday, the highway patrol reported a minimum of accidents and stranded travelers. Most schools were closed and other activities were curtailed. Many utility lines were down. Record December snowfall amounts were recorded for more than 40 locations in Minnesota. Artichoke Lake in Big Stone County received 16 inches of snow from this storm, by far its largest daily snowfall on record for any month of the year. Clear Lake, in Deuel County, measured 18 inches of snow, which also remains the largest daily snowfall on record for any month in that location. Watertown and Bryant received nine inches from this blizzard, while Castlewood reported seven inches.

• 1984: Strong winds gusted to 60 mph in the western through north central parts of South Dakota during the morning of the 21st.

• 1944: The Battle of the Bulge lasted from December 16, 1944 to January 25, 1945. By this time Germany was clearly losing World War II and Hitler was hoping to regain advantage if the attack would occur in bad weather to prevent the Allied Air Forces from being effective. As the Americans occupied the strategic position of Bastogne, the German army surrounded the city. However because of bad weather, planes were unable to fly and provide supplies by air drop to the American Forces. On December 29 the weather finally cleared up and much needed supplies were received. The Americans then launched a counteroffensive, but soldiers had to fight the cold and snow as well.

• 1967: The City Hall and a large portion of the business district of Potosi, MO was destroyed by an F4 tornado. There were 52 injuries and 3 deaths.