What is the longest time Chicago has gone without any precipitation?

Dear Tom,
What is the longest time Chicago has gone without any precipitation?
— Norma Friedemann, Evanston
Dear Norma,
After a very wet spring and early summer, it has certainly turned bone dry in the Chicago area. Since Aug. 4, the city has logged just 1.03 inches, the least on record for that period dating to 1871. The city’s record for absolutely no precipitation is 22 days, from Sept. 2-23, 1979. One-hundredth of an inch of rain fell Sept. 1 and a trace Sept. 24. Another trace of rain occurred Sept. 30, making the month’s total precipitation a meager 0.01-inch and crowning September 1979 the driest month in Chicago weather history. Chicago’s longest stretch of days with no measurable precipitation (none or traces) occurred Jan. 7-Feb. 5, 1919, a 30-day period.
Chicago’s record for absolutely no precipitation is 22 days, from Sept. 2-23, 1979.