Standardized Precipitation Index Table

Central Basin Climate Division

Washington, Climate Division 08

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.) 0.73 1.53 3.44 5.66 7 7.7 8.11 8.61 8.72 8.88 9.34 10.55 12.76 16.87 21.85 27.99 29.32 37.4 45.85 55.85
Accumulated Precipitation Departure from Normal (in.) -0.13 -0.37 0.17 0.84 0.73 0.64 0.6 0.83 0.69 0.18 -0.12 0.4 -0.66 -0.35 1.54 0.63 -1.12 -3.19 -4.91 -5.09
Accumulated Precipitation Percent of Average 85 80 105 117 112 109 108 111 109 102 99 104 95 98 108 102 96 92 90 92
Accumulated Precipitation Percentile (non-exceedance) 46.4 37.4 60.5 74.9 69.4 66.6 65.2 69.7 67 56.6 50.5 60.3 41.1 46.8 71.4 58.9 39.3 23.4 15.2 16.4
Standardized Precipitation Index -0.09 -0.32 0.27 0.67 0.51 0.43 0.39 0.52 0.44 0.17 0.01 0.26 -0.22 -0.08 0.57 0.22 -0.27 -0.72 -1.03 -0.98