Cold pattern would reverse winter trend of recent decades
Winters have warmed dramatically in Chicago over recent decades. At Midway Airport, the average December through February temperature—the period referred to as meteorological winter—increased 5° from the 1970s to the 1990s. An analysis of Chicago’s winter temperatures reveals the greatest proportion of the warming recorded during that period occurred in Januarys and Februarys. That’s why indications of a major shift to colder weather this weekend through the remaining days of January and the opening week of February are so interesting. That would reverse the trend observed in recent decades for winters to start off cold and stormy then ease dramatically.
Despite cooling in recent days, Winter 2006-07 still ranks 9th mildest among the 137 winters on the books here. This season’s mild readings have slashed the number of single digit or colder lows in half—from 12 to 6.
---By Tom Skilling, WGN-TV Chief Meteorologist