Standardized Precipitation Index Table

Western Climate Division

Massachusetts, Climate Division 01

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.) 2.24 5.63 8.37 13.03 16.3 18.58 22.43 25.49 33.32 37.57 41.35 44.28 53.31 61.12 86.79 118.76 147.27 196.45 254.2 296.77
Accumulated Precipitation Departure from Normal (in.) -1.18 -1.65 -2.85 -2.08 -3.08 -5.12 -5.71 -6.89 -3.14 -2.82 -2.9 -3.06 -5.34 -10.03 -7.99 0.09 4.99 6.84 17.31 12.65
Accumulated Precipitation Percent of Average 65 77 75 86 84 78 80 79 91 93 93 94 91 86 92 100 104 104 107 104
Accumulated Precipitation Percentile (non-exceedance) 23.2 25.1 15 30.1 23.7 14.1 13.9 11.4 32 34.5 34.2 33.4 24.4 12.7 22 51.6 65.9 67.7 83.1 73.6
Standardized Precipitation Index -0.73 -0.67 -1.04 -0.52 -0.71 -1.08 -1.08 -1.21 -0.47 -0.4 -0.41 -0.43 -0.69 -1.14 -0.77 0.04 0.41 0.46 0.96 0.63