Standardized Precipitation Index Table

Central Climate Division

Massachusetts, Climate Division 02

Precipitation Data Table

Time Scale in Months (As of the end of Apr. 2026)
1 2 3 4 5 6 7 8 9 10 11 12 15 18 24 30 36 48 60 72
Accumulated Precipitation (in.) 2.05 5.85 7.39 10.05 13.32 15.5 20.27 23.33 25.77 29.1 31.62 40.03 51.48 60.47 79.07 109.2 143.52 188.22 245.83 286.73
Accumulated Precipitation Departure from Normal (in.) -1.77 -1.9 -3.57 -4.43 -5.09 -6.79 -5.76 -6.54 -7.98 -8.6 -9.9 -5.11 -4.64 -6.99 -11.23 -3.49 7.96 7.62 20.26 16.26
Accumulated Precipitation Percent of Average 54 75 67 69 72 70 78 78 76 77 76 89 92 90 88 97 106 104 109 106
Accumulated Precipitation Percentile (non-exceedance) 11.8 22.1 7.5 5.7 5.4 2.7 9.2 8.6 6.8 7 5.5 23 26.9 20.1 14.4 39.4 72.8 68.7 85.2 77.4
Standardized Precipitation Index -1.19 -0.77 -1.44 -1.58 -1.6 -1.92 -1.33 -1.37 -1.49 -1.48 -1.6 -0.74 -0.62 -0.84 -1.06 -0.27 0.61 0.49 1.05 0.75