Dear Tom,
Looking at radar during heavy rains, it seems as though Chicago’s Loop does not get as much rain as the northwest or southern suburbs do. Is this just a coincidence? Is it my imagination?
Mike, Lake County, Ill. 

Dear Mike,
Averaged over enough time, perhaps a few years, the occurrence of heavy rain works out to arrive at all places in metropolitan Chicago with approximately the same frequency. Sometimes there is widespread heavy rain across the entire area, but more frequently it will rain more heavily in a given location. However, data show that the particular location receiving the largest rainfall total in any given weather situation does not favor any one location over any other.

Chicago’s official weather observation station was located in a few places in the Loop from the inception of records on Nov. 1, 1870, through 1925, then at the University of Chicago on the south side, then at Midway Airport and O’Hare International Airport. Heavy rainfall has occurred at each of those locations at various times in the past and no spot has been either favored or missed.