Indiana flirts with frost, Minnesota shivers at 18°
History proves an invaluable guide on the time frame for frost here. Residents of west suburban areas see frost first each fall—often sometime in the next week or two. By contrast, heat generated within the city delays frost’s arrival until the final week of October. In fact, the Loop proper may not expect to see frost most years until the first week of November.
The cool air behind Thursday morning’s frigid temperatures —including 18° at Embarrass, Minn.—threatened protected areas of northern Indiana and southwest Lower Michigan with patchy frost Friday morning.
Chicago’s 62° high Thursday was its coolest daytime reading since May and only the third afternoon high which has failed to reach 70° since June 1. There’s not been another year since records began in 1871 that has come even close to producing so few sub-70° temperatures in the June 1 through Sept. 30 period. The average is 22.
