Standardized Precipitation Index Table

Southwest Valleys Climate Division

Idaho, Climate Division 05

Precipitation Data Table

Time Scale in Months (As of the end of Jan. 2026)
1 2 3 4 5 6 7 8 9 10 11 12 15 18 24 30 36 48 60 72
Accumulated Precipitation (in.) 1.11 3.78 4.44 5.79 6.55 7.05 7.58 7.71 8.36 8.86 10.27 13.71 19.75 20.87 28.12 35.83 42.64 54.97 67.27 80.13
Accumulated Precipitation Departure from Normal (in.) -0.67 0.21 -0.73 -0.35 -0.16 0.02 0.24 -0.61 -1.24 -1.93 -1.95 0.02 0.87 0.13 0.72 1.42 1.58 0.25 -1.12 -1.93
Accumulated Precipitation Percent of Average 62 106 86 94 98 100 103 93 87 82 84 100 105 101 103 104 104 100 98 98
Accumulated Precipitation Percentile (non-exceedance) 22.3 60.8 38.1 46.3 49.8 53.7 58.5 39.9 30 20.3 21 52.7 62.8 53.7 59.5 64.2 64.6 53.2 43.5 39.3
Standardized Precipitation Index -0.76 0.27 -0.3 -0.09 0 0.09 0.21 -0.26 -0.52 -0.83 -0.81 0.07 0.33 0.09 0.24 0.36 0.37 0.08 -0.16 -0.27