Standardized Precipitation Index Table

North Central Climate Division

Montana, Climate Division 03

Precipitation Data Table

Time Scale in Months (As of the end of Jul. 2020)
1 2 3 4 5 6 7 8 9 10 11 12 15 18 24 30 36 48 60 72
Accumulated Precipitation (in.) 0.81 4.45 6.58 7.4 8.19 8.81 9.4 9.92 11.32 12.16 15.03 16.58 22.67 25.71 31.02 39.96 45.46 60.93 78.31 94.41
Accumulated Precipitation Departure from Normal (in.) -0.71 -0.02 -0.09 -0.43 -0.47 -0.49 -0.69 -0.92 -0.28 -0.31 1.24 1.48 0.9 1.3 0.83 0.47 0.23 0.68 3.07 4.2
Accumulated Precipitation Percent of Average 53 100 99 95 95 95 93 91 98 98 109 110 104 105 103 101 101 101 104 105
Accumulated Precipitation Percentile (non-exceedance) 25.2 54.6 52.4 45.5 44.7 44.2 40.8 36.4 48 47.4 70.3 72.3 61.8 65.7 60.1 55.7 53.4 56.7 72.9 77.5
Standardized Precipitation Index -0.67 0.11 0.06 -0.11 -0.13 -0.15 -0.23 -0.35 -0.05 -0.07 0.53 0.59 0.3 0.4 0.26 0.14 0.09 0.17 0.61 0.75