Standardized Precipitation Index Table

Northeastern Climate Division

Washington, Climate Division 09

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.) 2.06 4.29 7.34 10.79 13.15 13.94 15.43 17.4 17.69 18.86 21.44 24.19 28.72 36.67 46.43 59.22 64.05 86.01 106.96 127.16
Accumulated Precipitation Departure from Normal (in.) 0.16 0.36 0.78 1.39 0.92 -0.05 0.24 1.29 0.68 -0.07 0.48 1.6 -0.42 0.07 1.25 0.06 -3.69 -4.26 -5.86 -8.18
Accumulated Precipitation Percent of Average 108 109 112 115 107 100 102 108 104 100 102 107 99 100 103 100 95 95 95 94
Accumulated Precipitation Percentile (non-exceedance) 62.8 64.4 69.9 75.5 65.5 52.3 55.7 67.6 60.6 51.7 57.3 67.8 48.3 52.4 60 51.9 32.2 32.7 29.2 24.2
Standardized Precipitation Index 0.32 0.37 0.52 0.69 0.4 0.06 0.14 0.46 0.27 0.04 0.18 0.46 -0.04 0.06 0.25 0.05 -0.46 -0.45 -0.55 -0.7