Dear Tom,
My husband and I consider spring to start when the average high temperature reaches 50(degrees). When does that happen in Chicago?
Catherine Bouxsein Evanston, Ill.
Dear Catherine,
Chicago’s average high temperature began its annual upswing on Jan. 22 when it rose from 29(degrees) to 30(degrees). It will reach the 50(degrees) benchmark on March 25, five days after spring’s astronomical start on the March 20 vernal equinox.
Most meteorologists actually consider March 1 as the start of the three month meteorological spring season because by then, the atmospheric transition from a winter to a summer environment is already well underway.
Despite reaching that 50(degrees) value, Chicagoans know that plenty of chilly spring days lie ahead after March 25, as the ever present northeast winds off of icy Lake Michigan bring many days with high temperatures only in the 30s and 40s.
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Tom Skilling is chief meteorologist at WGN-TV. His forecasts can be seen Monday through Friday on WGN-TV News at noon and 9 p.m.
Write to: ASK TOM WHY, 2501 Bradley Pl., Chicago, IL 60618 or asktomwhy@wgntv.com (Mail volume precludes personal response.)
WGN-TV meteorologists Steve Kahn, Richard Koeneman and Paul Dailey plus weather producer Bill Snyder contribute to this page.
