Standardized Precipitation Index Table

Palouse Blue Mountains Climate Division

Washington, Climate Division 10

Precipitation Data Table

Time Scale in Months (As of the end of Mar. 2024)
1 2 3 4 5 6 7 8 9 10 11 12 15 18 24 30 36 48 60 72
Accumulated Precipitation (in.) 1.23 3.03 5.37 8.24 10.55 11.88 12.84 13.81 13.9 14.59 15.78 17.29 20.75 29.14 40.17 52.71 55.57 74.21 92.82 110.53
Accumulated Precipitation Departure from Normal (in.) -0.7 -0.76 -0.8 -0.51 -0.74 -0.93 -0.92 -0.58 -1.05 -1.81 -2.32 -2.36 -5.08 -3.36 0.82 0.53 -3.42 -4.43 -5.47 -7.4
Accumulated Precipitation Percent of Average 64 80 87 94 93 93 93 96 93 89 87 88 80 90 102 101 94 94 94 94
Accumulated Precipitation Percentile (non-exceedance) 21.9 29.9 33.7 43 41.1 39 40.1 44.4 37.7 28.3 23.9 23.8 6.9 20.4 58.7 55.4 26.8 24.7 22.1 16
Standardized Precipitation Index -0.77 -0.53 -0.42 -0.18 -0.22 -0.28 -0.25 -0.14 -0.31 -0.57 -0.71 -0.71 -1.48 -0.83 0.22 0.14 -0.62 -0.69 -0.77 -1