Standardized Precipitation Index Table

Northeastern Climate Division

Washington, Climate Division 09

Precipitation Data Table

Time Scale in Months (As of the end of Jan. 2026)
1 2 3 4 5 6 7 8 9 10 11 12 15 18 24 30 36 48 60 72
Accumulated Precipitation (in.) 1.35 4.72 7.98 10.52 11 11.74 12.1 12.41 13.83 15.13 17.69 19.98 30.12 32.01 41.11 54.22 63.35 85.86 102.97 125
Accumulated Precipitation Departure from Normal (in.) -1.26 -0.72 -0.32 0.46 -0.25 -0.42 -0.95 -2.55 -3.16 -3.47 -2.82 -2.56 -0.75 -2.72 -4.02 -3.09 -4.36 -4.35 -9.75 -10.24
Accumulated Precipitation Percent of Average 52 87 96 105 98 97 93 83 81 81 86 89 98 92 91 95 94 95 91 92
Accumulated Precipitation Percentile (non-exceedance) 10 36.4 47.9 60.3 49.7 46.8 39.5 20.4 17.1 15 22.1 26.3 45.1 30.2 25.6 33.1 28.7 32.1 16.8 18.3
Standardized Precipitation Index -1.28 -0.35 -0.05 0.26 -0.01 -0.08 -0.27 -0.83 -0.95 -1.04 -0.77 -0.63 -0.12 -0.52 -0.66 -0.44 -0.56 -0.46 -0.96 -0.9