Has Chicago ever had a month of April without a thunderstorm?

Dear Tom,
There has not been a thunderstorm yet this month. Has Chicago ever had a month of April without a thunderstorm?
— Brian Dzurisin, Downers Grove
Dear Brian,
It has, but it’s been quite a long time. The city’s last April without a thunderstorm dates back 66 years to 1952. In all, there have been 10 thunderless Aprils, with the other nine all occurring between 1873 and 1926, a period when the city’s weather observations were taken in downtown locations near chilly Lake Michigan. What’s even more interesting is the fact that if no thunderstorms occur through the end of the month, this could be only the fourth March-April tandem since 1871 without a thunderstorm and the first since 1915. The other two were in 1873 and 1885. The city’s last thunderstorm occurred on Feb. 20.
The city’s last April without a thunderstorm dates back 66 years to 1952.