It has been 10 days since an above-normal high temperature has officially been logged at O’Hare airport. This spell of cool days was partially due to clouds and frequent rain. Through June 24, rain has been observed on 15 days. Despite this high number, the month’s rain total was running about a quarter-inch below normal as of 6 p.m. Monday. Scattered thunderstorms may boost our rain total Tuesday night. An influx of warmer air Tuesday is also expected to start a period of warmth that is to carry into July.

The city is likely to experience its first 90-degree days of the season this week, and the transition to summer-level heat may be accompanied by a few thunderstorms, especially Thursday into Friday. Overall, most of the area will stay in tropical air through next week.