Standardized Precipitation Index Table

Yellowstone Drainage Climate Division

Wyoming, Climate Division 01

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.) 2.44 3.94 5.39 7.1 10.57 13.16 16.03 17.21 21.37 22.9 25.03 28.46 35.94 43.22 59.91 71.48 81.8 108.8 137.65 168.74
Accumulated Precipitation Departure from Normal (in.) 0.12 -1.24 -2.41 -3.27 -1.78 -0.96 0.43 0.08 1.71 0.38 -0.02 0.75 0.42 1.39 4.49 2.01 -1.23 -1.89 -0.62 2.87
Accumulated Precipitation Percent of Average 105 76 69 68 86 93 103 100 109 102 100 103 101 103 108 103 99 98 100 102
Accumulated Precipitation Percentile (non-exceedance) 60.4 26.4 14.2 12.7 29.9 41.4 57.8 53.7 69.5 56.1 52 59 55.2 61.2 76.3 61.8 45.3 43.6 48.8 60.3
Standardized Precipitation Index 0.26 -0.63 -1.07 -1.14 -0.53 -0.22 0.2 0.09 0.51 0.15 0.05 0.23 0.13 0.28 0.72 0.3 -0.12 -0.16 -0.03 0.26