Standardized Precipitation Index Table

North Central Prairies Climate Division

Idaho, Climate Division 02

Precipitation Data Table

Time Scale in Months (As of the end of Feb. 2026)
1 2 3 4 5 6 7 8 9 10 11 12 15 18 24 30 36 48 60 72
Accumulated Precipitation (in.) 3.86 5.8 12.84 15.87 18.13 19.57 20.41 21.07 21.64 23.18 24.85 28.03 38.8 46.68 56.91 72.36 83.04 115.08 139.36 170.11
Accumulated Precipitation Departure from Normal (in.) 0.79 -1.02 2.24 1.53 1.4 1.26 1.14 0.91 -0.93 -2.22 -3.18 -3.08 -2.92 -2.76 -5.36 -8.23 -10.4 -9.56 -16.5 -17.04
Accumulated Precipitation Percent of Average 126 85 121 111 108 107 106 105 96 91 89 90 93 94 91 90 89 92 89 91
Accumulated Precipitation Percentile (non-exceedance) 74.8 33.7 80 69.6 67.2 64.9 63.8 61.5 43.4 32.4 25.3 26 29.9 33.2 20.6 12.8 8.6 14 4.2 4.4
Standardized Precipitation Index 0.67 -0.42 0.84 0.51 0.44 0.38 0.35 0.29 -0.17 -0.45 -0.67 -0.64 -0.53 -0.43 -0.82 -1.14 -1.37 -1.08 -1.73 -1.7