Standardized Precipitation Index Table

Southwest Valleys Climate Division

Idaho, Climate Division 05

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.) 0.67 1.18 2.6 5.99 7.12 9.82 12.03 12.57 13.09 13.15 13.29 13.93 18.43 24.16 29.42 38.67 42.68 55.77 67.79 79.1
Accumulated Precipitation Departure from Normal (in.) -0.61 -1.29 -1.3 0.61 -0.04 0.86 1.47 1.05 0.99 0.73 0.57 0.22 0.81 1.52 2.03 2.38 1.64 1.06 -0.58 -2.94
Accumulated Precipitation Percent of Average 52 48 67 111 99 110 114 109 108 106 104 102 105 107 107 107 104 102 99 96
Accumulated Precipitation Percentile (non-exceedance) 26.6 9.4 17.2 67.8 52.8 67.4 74.1 68.3 67.5 63.9 61.3 55.9 63.2 69 71.7 71.5 64.8 58.9 47.3 33.6
Standardized Precipitation Index -0.63 -1.31 -0.95 0.46 0.07 0.45 0.64 0.48 0.45 0.35 0.29 0.15 0.34 0.5 0.57 0.57 0.38 0.23 -0.07 -0.42