Text size:

ASK TOM WHY

With Tom Skilling

January 31, 2009

Dear Tom,

What has been Chicago's greatest snow depth at any one time?

—Adam Zlotnicki, 9

Dear Adam,

Many people think that Chicago's deepest snow cover occurred in the wake of the city's 23-inch "Big Snow" of Jan. 26-27, 1967. Additional snowfalls after the huge storm caused the city's snow cover to increase, reaching 28 inches on Feb. 6 and 7, establishing a record depth at that time. However, that record was eclipsed during the city's benchmark winter of 1978-79 that recorded 89.7 inches of snow. Chicago's snowpack reached 29 inches on Jan. 14, 1979, after 21 inches of snow fell from Jan. 11-14 during the "Blizzard of '79." That winter also holds the record for consecutive days of snow cover: 100 days, from Nov. 26-March 5.