Highs reached the 70s Thursday, with the 74 degrees at Midway Airport tying the record set in 1975. It was 72 at Chicago's official site at O'Hare International Airport. The unseasonable weather will come to a screeching halt Friday afternoon as a cold front swings through from the west.

Temperatures on Friday morning should reach the 60s, but afternoon southern winds will shift west with temperatures tumbling into the 50s, then 40s by evening as a strong cold front with showers and a few thunderstorms march through northeast Illinois into northwest Indiana. Overnight, with colder air riding gusty northwest winds, readings will fall into the 20s with the season's first snowflakes likely. Snow showers and flurries could continue Saturday with temperatures in the mid to upper 30s.