For much of the Midwest, December will be remembered as a particularly active month of weather. Chicago received 17.7” of snow, making it the 8th snowiest December on record. In addition to a healthy amount of snow, the Midwest also had by far its coldest air of the season push in during mid-December, in a two part arctic blast.
An arctic high pressure dropped south out of Canada and settled across the Midwest December 13th, ushering in the coldest air of the season. Portions of the Upper Midwest saw the brutally cold temperatures first, as Minneapolis had low temperatures approaching -10° F on December 13th – 15th. This arctic air then pushed southeastward and settled across the Chicago, Indianapolis, and Columbus, where low temperatures were 15 – 25 degrees below average. Low temperatures at Chicago O’Hare International Airport were in the single digits the 13th and 14th and even dropped to -2° F on the 15th!
Despite much of the Midwest briefly warming up on the 16th and 17th, a second reinforcing punch of arctic air dropped temperatures even lower the 18th and 19th, particularly in Chicago. Low temperatures dropped to nearly 30 degrees below average to -11°F (18th) and -13° F (19th) at Rockford International Airport. Even areas further southeast, like Indianapolis, saw lows in the single digits and negative single digits. Temperatures rebounded quickly, returning closer to normal starting on the 20th. Despite the mild end to the month, this blast of arctic air will likely not be forgotten anytime soon!
