Dear Tom,

The consensus is that it’s safe to plant after Memorial Day. Have we ever had frost in June?

Thanks, Merle G. Antioch

Dear Merle,

Frost in the Chicago area in June is extremely rare, though it has occurred in the month’s opening days. The record lows for the first six days of June are all in the 30s, the lowest 35 on June 4, 1945. That morning frost was reported at several locations in northern Illinois, including Midway Airport. The previous day, June 3, with an unseasonably chilly high of just 48 and a low of 37 is the coldest June day ever in Chicago with an average temperature of 42.5 degrees. Though technically tied if rounded, the runner-up was June 5, 1894, with an average of 43 degrees, based on a high of 45 and a low of 41. Beyond June 6, the city’s next low in the 30s is on September 13, when the mercury dropped to 39 in 1890.