Dear Tom,
Has this cool summer had an effect on when trees typically change their colors?
Michael Stack, Lake Zurich
Dear Michael,
That exact topic has resurfaced among forest professionals–park rangers, botanists, and the DNR agents that issue the fall color outlooks. Since fall colors are mostly triggered by length of day, seasonal color change should occur about the same time each year, but it doesn’t. Spring, summer, and early fall rainfall leading up to the change plays a role, and here in Chicago trees were stressed by the variability of rainfall, suggesting an early change. However, in other parts of the Midwest the rainfall was near normal, and still the fall colors are changing early after such a cool summer. Areas in the northern highlands of Wisconsin/Minnesota, which received an August freeze are leading the quick change.
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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.
