Two days before Chicago’s 23-inch blizzard of January 1967, conditions were unseasonably warm. Did that have anything to do with the amount of snow that fell?
The warmth sent Chicago-area temperatures surging to a 65-degree record high on Jan. 24 and undoubtedly added to the severity of the storm. The warm air flooding into the Midwest fed large amounts of moisture into the system, fueling severe thunderstorms and heavy rainfall. When the cold air arrived, the sharply contrasting temps resulted in rapid cyclogenesis (storm formation), and with large amounts of moisture in the air, heavy snow began to fall. The storm’s first wave produced about a foot; an unexpected second low-pressure system formed, nearly doubling the snow totals.