Standardized Precipitation Index Table

North Central Climate Division

Iowa, Climate Division 02

Precipitation Data Table

Time Scale in Months (As of the end of May 2025)
1 2 3 4 5 6 7 8 9 10 11 12 15 18 24 30 36 48 60 72
Accumulated Precipitation (in.) 2.51 6.97 10.59 11.05 11.09 12.24 15.27 16.33 17.09 20.41 25.4 33.09 49.39 52.08 65.55 78.66 94.2 125.09 151.38 186.97
Accumulated Precipitation Departure from Normal (in.) -1.76 -0.24 1.56 1.1 0.29 0.35 1.78 0.59 -2.18 -2.86 -1.77 1.15 8.44 8.25 1.68 2.95 -1.6 -2.73 -8.5 -5.06
Accumulated Precipitation Percent of Average 59 97 117 111 103 103 113 104 89 88 93 104 121 119 103 104 98 98 95 97
Accumulated Precipitation Percentile (non-exceedance) 15.6 50.8 73.7 67.7 57.4 57.9 72.9 59.5 31.6 27.6 37.8 60.6 89.8 88.7 59.9 64.1 45.2 42.4 27.8 37.9
Standardized Precipitation Index -1.01 0.02 0.63 0.46 0.19 0.2 0.61 0.24 -0.48 -0.59 -0.31 0.27 1.27 1.21 0.25 0.36 -0.12 -0.19 -0.59 -0.31