Standardized Precipitation Index Table

Central Climate Division

Montana, Climate Division 04

Precipitation Data Table

Time Scale in Months (As of the end of Feb. 2024)
1 2 3 4 5 6 7 8 9 10 11 12 15 18 24 30 36 48 60 72
Accumulated Precipitation (in.) 1.28 1.94 2.22 2.68 4.24 6.61 7.88 8.67 13.63 16.58 18.17 19.37 22.1 26.69 37.16 41.15 49.1 65.06 84.54 104.84
Accumulated Precipitation Departure from Normal (in.) 0.44 0.12 -0.59 -1.13 -0.73 0.17 0.09 -0.7 1.22 1.45 1.53 1.61 1.51 2.48 1.64 -0.79 -4.15 -5.95 -4.2 -1.62
Accumulated Precipitation Percent of Average 151 106 79 70 85 103 101 93 110 110 109 109 107 110 105 98 92 92 95 98
Accumulated Precipitation Percentile (non-exceedance) 85.5 61.5 28.5 16.9 29.9 57.4 55 39.2 70.4 70.4 71 71.5 69.3 76.3 65.8 44.7 22.6 17.4 28.2 42.7
Standardized Precipitation Index 1.06 0.29 -0.57 -0.96 -0.53 0.19 0.13 -0.27 0.54 0.54 0.55 0.57 0.51 0.72 0.41 -0.13 -0.75 -0.94 -0.58 -0.18