Standardized Precipitation Index Table

Southwest Climate Division

Iowa, Climate Division 07

Precipitation Data Table

Time Scale in Months (As of the end of Sep. 2020)
1 2 3 4 5 6 7 8 9 10 11 12 15 18 24 30 36 48 60 72
Accumulated Precipitation (in.) 2.79 3.54 7.53 9.83 14.49 16.47 18.73 18.82 19.9 20.82 21.57 26.43 40.65 54.6 68.93 97.68 108.59 140.03 186.11 229.97
Accumulated Precipitation Departure from Normal (in.) -0.93 -4.31 -4.22 -6.75 -6.46 -7.5 -7.13 -8.05 -7.81 -7.96 -8.78 -6.43 -4 -2.29 3.17 7.93 9.99 8.61 21.83 32.93
Accumulated Precipitation Percent of Average 75 45 64 59 69 69 72 70 72 72 71 80 91 96 105 109 110 107 113 117
Accumulated Precipitation Percentile (non-exceedance) 39.6 5 13.7 4.1 8.6 6 8.8 6.1 7 7.3 5.9 15.8 32 41.4 64.7 76.9 80.4 73.8 91.2 96.7
Standardized Precipitation Index -0.26 -1.65 -1.09 -1.74 -1.37 -1.55 -1.35 -1.54 -1.48 -1.45 -1.57 -1 -0.47 -0.22 0.38 0.73 0.85 0.64 1.36 1.84