On Saturday, November 11, 1911, a cold snap, known as the Great Blue Norther of 11/11/11, affected the Central United States.

[3] A blizzard even occurred within one hour after an F4 tornado hit Rock County, Wisconsin.

[5] Alongside the dramatic temperature swings, the cold front brought a destructive tornado outbreak to parts of the Midwest.

Hundreds of structures were destroyed by the storms and many areas had to conduct search and rescue missions amidst blizzard conditions.

Dramatic cold snaps tend to occur mostly in the month of November, though they can also come in February or March.

Although temperature drops of this extent have happened on other occasions, as recently as February 2009, the fact that the 1911 cold front passage was during the autumn and came after such warm weather contributed to the properties mentioned in this article.

[8] Between November 10 and 11th, Denver experienced its eleventh largest two day temperature swing, from 66 to −2 °F (19 to −19 °C), which is a 68 °F (38 °C) change.

[9] On November 11, temperatures in Kansas City had reached a record high of 76 °F (24 °C) by late morning before the front moved through.

[19] In Chicago, Illinois, people died separately of heatstroke and cold, respectively, within 24 hours, the first such incidence on record in the city.

Other intense tornadoes occurred in Illinois and Indiana, resulting in four additional fatalities.

Tornado researcher Thomas P. Grazulis considered the outbreak to be the worst in the month of November on record at the time in the Great Lakes region.

[3] The passage of a cold front, marked by strong winds, produced severe weather, including tornadoes, across the upper Mississippi River Valley, a blizzard in Ohio, and a dust storm in Oklahoma.