Iowa, Precipitation Rankings, December 2019 1901-2000 Inches 1 1.28 1.11 0.17 82 47 2002 2015 2017 2018 normal 2003 2 2.77 2.87 -0.10 65 64 1976 2015 2017 2018 normal 3 7.55 5.16 2.39 114 15 1910 1931 2017 2018 top-third 4 13.76 8.83 4.93 120 9 1939,1976 1931 2017 2018 top-tenth 5 17.29 12.67 4.62 115 14 1976 2018 2017 2018 top-third 6 20.67 16.52 4.15 106 23 1976 2018 2017 2018 top-third 1987 7 24.58 21.15 3.43 100 29 1976 2018 2017 2018 top-third 8 32.79 25.20 7.59 121 8 1976 1993 2017 2018 top-tenth 9 35.82 28.15 7.67 117 12 1910 1993 2017 2018 top-tenth 10 38.01 30.10 7.91 117 12 1910 1993 2017 2018 top-tenth 11 40.35 31.12 9.23 119 10 1910 1993 2017 2018 top-tenth 12 41.63 32.09 9.54 119 10 1910 1993 2017 2018 top-tenth 18 68.08 48.69 19.39 126 2 1956 1993 2018 1993 top-tenth 24 86.71 64.24 22.47 127 1 1989 2019 2018 2019 highest 36 119.07 96.36 22.71 122 5 1957 2010 2018 2016 top-tenth 48 157.17 128.37 28.80 121 5 1958 2010 2017 2018 top-tenth 60 199.70 160.36 39.34 122 3 1956 2010 2018 2011 top-tenth