Standardized Precipitation Index Table

North Central Climate Division

Iowa, Climate Division 02

Precipitation Data Table

Time Scale in Months (As of the end of Jul. 2020)
1 2 3 4 5 6 7 8 9 10 11 12 15 18 24 30 36 48 60 72
Accumulated Precipitation (in.) 2.39 7.54 12.52 13.75 16.66 17.39 18.58 19.87 21.85 27.47 32.86 35.71 50 57.74 82.26 106.85 119.76 161.65 202.87 236.59
Accumulated Precipitation Departure from Normal (in.) -1.53 -1.16 -0.44 -2.13 -1.02 -1.23 -0.88 -0.7 -0.32 3.04 4.84 3.7 5.02 7.1 18.28 24.27 23.91 33.91 43.32 45.27
Accumulated Precipitation Percent of Average 61 87 97 87 94 93 95 97 99 112 117 112 111 114 129 129 125 127 127 124
Accumulated Precipitation Percentile (non-exceedance) 20.5 37 48.3 31.6 43.3 41.5 44.6 46.4 49.7 75.4 83 75.6 77.1 82.6 98.1 98.9 98.6 99.5 99.8 99.8
Standardized Precipitation Index -0.83 -0.33 -0.04 -0.48 -0.17 -0.21 -0.13 -0.09 -0.01 0.69 0.96 0.69 0.74 0.94 2.08 2.3 2.19 2.55 2.92 2.85