Standardized Precipitation Index Table

South Central Climate Division

Iowa, Climate Division 08

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.) 2.72 5.55 7.69 8.23 9.05 10.94 14.06 16.6 18.03 21.67 26.71 30.47 44.01 48.95 63.54 75.37 91.41 127.6 158.44 195.49
Accumulated Precipitation Departure from Normal (in.) -1.65 -2.15 -2.1 -2.7 -2.99 -2.41 -1.16 -1.26 -3.68 -4.06 -2.98 -4.02 -0.29 1.11 -5.46 -6.87 -12.03 -10.39 -14.08 -11.65
Accumulated Precipitation Percent of Average 62 72 79 75 75 82 92 93 83 84 90 88 99 102 92 92 88 92 92 94
Accumulated Precipitation Percentile (non-exceedance) 20.5 22.6 26.8 20.5 18.6 25.6 41.2 40.9 24.6 24 34 29 50.8 57.6 29.8 26.6 15.8 24 19.7 26.5
Standardized Precipitation Index -0.82 -0.75 -0.62 -0.82 -0.89 -0.65 -0.22 -0.23 -0.69 -0.71 -0.41 -0.55 0.02 0.19 -0.53 -0.62 -1 -0.71 -0.85 -0.63