South winds gusting near 40 mph Monday afternoon swept tropical air into the Midwest. Temperatures throughout the region climbed as high as 86 at Peru and Pontiac. The 85-degree reading observed at Midway Airport fell just one degree short of the record for Oct. 17, set there in 1950. Area low temperatures also were remarkable. The city's official low of 67 at O'Hare International Airport was 5 degrees above the normal high. To put Monday's abnormal warmth in perspective, had Midway's high of 85 and low of 69 occurred July 15, the average temperature for the day would have been 3 degrees above normal. Despite another summer-like start to the day, Tuesday's high temperature is forecast in the mid-70s. Cooler, less humid air should arrive as winds turn northwest after a morning cold front.