DES MOINES, IOWA — The first freeze is expected to arrive slightly later than average this year across the Corn Belt and Central Plains, largely due to an unusually warm September, with Midwest Weather projecting widespread freezing temperatures to reach Des Moines and Chicago only by the end of October, while areas further south, including much of Iowa and Illinois, wait even longer.
Warm September Pushes Back the Seasonal Timeline
According to the forecast, this year’s unusually warm September is the primary driver behind the delayed freeze timeline. Even as temperatures cool during the second half of the month, forecasters note that first frosts will be possible across parts of the Upper Midwest, though temperatures will likely struggle to fall into the 20s and lower 30s on a widespread basis during that early cooling period.
Early October Freeze Targets the Far Northern Plains
The earliest widespread freeze, projected for early October and shown in pink on the outlook map, is expected across the far northern tier, including Williston, Minot, Grand Forks, and International Falls. This northernmost zone, closest to the Canadian border, typically sees the season’s first freeze well ahead of areas farther south, a pattern that holds true even in a year running behind the average timeline.
Mid-October Freeze Reaches Bismarck, Fargo, and Minneapolis
Moving south from the earliest freeze zone, a Mid-October timeframe, shown in purple, covers a broad swath including Bismarck, Fargo, Minneapolis-St Paul, and Green Bay, extending east through much of Michigan, including Traverse City and Marquette. This zone represents the core Upper Midwest, where residents can typically expect their first widespread freeze to arrive around the midpoint of October in a typical year…