Dear Tom,

My daughter lives in Houston where not only are the days hot and humid, but overnight lows frequently hold in the 80s. That doesn’t seem to happen here, does it?

—Frank Chatsworth

Dear Frank,

It does happen, but not very often. It’s been nearly three years since the city’s overnight temp failed to drop below 80, since a low of 81° on July 19, 2019. Overnight lows temps of 80° or higher are rare in Chicago, having occurred only 33 times in 20 different years, dating back to 1871. In those 20 years, 13 years have recorded a single occurrence, and six years have recorded two, most recently 1995 and 2012. The summer of 1916 trounces all other years with eight such days and includes the city’s all-time highest minimum of 85° on July 29, the pinnacle of a five-day run from July 26-30. In 1916, the city’s official temps were taken downtown at 219 S. Clark Street.