Southwest breezes brought very warm, more humid air into the upper Midwest on Monday. Officially, the city recorded its first 90 degree day since July 20th. Though humidity levels across northeast Illinois and northwest Indiana remained modest by summertime standards, sultry, 70-degree dew point air spread across areas just to our north and west. The influx of sticky air fueled severe thunderstorms that were prolific hail producers. As of 6 PM Monday, 34 large hail reports were logged, mostly across Minnesota. Stones to 4 inches in diameter fell at Delano, just northwest of the Twin Cities. The cold front that triggered the severe weather will be moving through the Chicago area on Tuesday, raising the likelihood of scattered thunderstorms. Severe weather is not expected, but some areas may receive much needed rain. Drier, stable air is expected to arrive during the midweek period.