Standardized Precipitation Index Table

Northeastern Climate Division

Montana, Climate Division 06

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.) 0.12 0.18 1.13 1.71 3.02 3.4 4.98 8.75 10.51 12.29 13.32 13.53 14.79 16.82 25.68 29.48 39.59 52.13 60.4 70.44
Accumulated Precipitation Departure from Normal (in.) -0.22 -0.57 0.01 0.17 0.69 -0.08 0.14 2.07 0.97 0.69 0.73 0.4 0.52 0.2 -0.59 -0.26 0.19 -0.42 -5.28 -8.42
Accumulated Precipitation Percent of Average 35 24 101 111 130 98 103 131 110 106 106 103 104 101 98 99 100 99 92 89
Accumulated Precipitation Percentile (non-exceedance) 10.8 1.3 55.6 66 82.1 52.2 57.7 88.5 69.2 62.7 62.6 58.3 59.7 55 46.1 49.3 53.2 48.6 21.6 12.4
Standardized Precipitation Index -1.24 -2.23 0.14 0.41 0.92 0.05 0.19 1.2 0.5 0.32 0.32 0.21 0.24 0.13 -0.1 -0.02 0.08 -0.03 -0.79 -1.15