Temperatures climbed to the mid and upper 80’s across the metro area on Monday as southwest winds swept tropical air across the Midwest. Officially, at O’Hare airport, the day posted a temperature surplus of 16 degrees, boosting the month’s average to 4.8 degrees above normal, and making this the 15th warmest September on record. The month also closed with 7.61 inches of rainfall, ranking September, 2019 as the 6th wettest. Tropical air can bring heavy rains, but a large heat dome to our south has suppressed storm development. Another day of July-level warmth is on tap for Tuesday, though highs will likely fall short of the 92-degree record for the date. Muggy, high dew point air will keep nighttime readings warm, putting the record high minimum of 71 for October 1st in jeopardy. Cooling air is to arrive midweek, with a stronger push of autumnal air set to arrive Thursday into Friday.