A cloudy and blustery Saturday may bring the season’s first snowflakes to the Chicago area, a couple of days ahead of the October 30 average date and a full three weeks ahead of last year when the first flakes of snow didn’t fall until November 19.
Skies will clear overnight, allowing temperatures to plunge below freezing across most of the Chicago area, with the exception of locations in the heart of the city and in close proximity to the lake.
Southwest winds will deliver slightly milder, but still below normal high temperatures in the middle and upper 40s on Sunday and Monday.
Colder air will return on Halloween following a cold front passage, limiting high temperatures to the lower 40s which would bring the city its chilliest Halloween in 21 years, since a 40-degree high in 1996.
Milder conditions will follow the rest of the week with the mercury rebounding to near 60 by next weekend.