average rainfall in Michigan
1 Michigan Annual Precipitation Average - 32.84 inches, 32nd wettest state in the U.S. 2  Michigan Tornado Average - 16.1 per year - 20th most in the U.S.3  Largest reported Tornado in Michigan from 1950-2011, 7/2/1997 - 2,500 yards / 1.42 miles wide. Record Driest year in Michigan from 1895-2012 - 1930, avg precipitation 22.31 inches. 2  Record Wettest year in Michigan from 1895-2012 - 1985, avg precipitation 39.48 inches.