SEPTEMBER IN GREAT LAKES COUNTRY is the most honest month. July flatters. August lingers past its welcome. October arrives dressed for drama. But September simply is: the light sharpening, the lake shrugging off the last of summer’s warmth, the air carrying that particular mixture of damp earth and cooling water that makes you pull your jacket one morning and realize the season has moved on without asking permission.
Today is a fine September day. The high of 72 degrees we are tracking for this afternoon is precisely what a September should be: comfortable without being warm, clear without being cold. The northwest wind off the lake is the kind that doesn’t so much blow as remind you it’s there — eight to twelve miles per hour, enough to move the flags at the new factory and raise a small chop on the water but not enough to trouble a ceremony or a hockey opening night.
The week ahead, however, is a Great Lakes week: variable, with the season making its intentions increasingly clear by Sunday. The showers forecast for Sunday afternoon are part of a frontal system tracking southeast from Minnesota, and while they will not be severe — half an inch of rain at most — they will mark the effective end of summer weather in this area. The temperatures through the following week will settle into the low-to-mid sixties for highs, which is where September wants to be.
One note for gardeners and anyone with plants still in the ground: Monday night may see temperatures approaching 43 degrees, which is near the threshold for a frost warning. Herb Fencl, who writes the Tribune’s “Ask the Almanac” column, advises covering any remaining tender plants — tomatoes, peppers, basil — Sunday night or Monday morning. “Don’t wait until you can see your breath,” Fencl says. “By then it’s already been decided.”
The lake itself is currently at 64 degrees, which Burkhalter says is “warm enough for a brave swimmer but cold enough to be instructive.” Lake temperatures will drop through September toward the upper fifties and into the forties by October, following the usual Great Lakes calendar.