The NOAA gives rainfall totals for Chicago/O'Hare, which is the closest "official" tally, at: http://www.crh.noaa.gov/lot/?n=ordmonthly
Just select a month and check the "PCPN/WTR" column (precipitation/water...as opposed to snow).
Hope this is helpful!
--Bill Pardue
Arlington Heights Memorial Library http://www.ahml.info
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