Standardized Precipitation Index Table

Coastal Climate Division

Massachusetts, Climate Division 03

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.) 9.04 11.07 18.87 24.89 26.81 29.41 35.81 41.8 47.53 52.17 55.16 58.34 72.46 86.68 103.04 126.82 159.21 199.78 251.8 306.62
Accumulated Precipitation Departure from Normal (in.) 4.79 3.32 7.2 9.05 6.85 5.6 8.33 10.57 13.07 14.34 13.95 13.11 15.62 17.71 12.71 12.74 23.73 19.25 26.32 36.21
Accumulated Precipitation Percent of Average 213 143 162 157 134 124 130 134 138 138 134 129 127 126 114 111 118 111 112 113
Accumulated Precipitation Percentile (non-exceedance) 97 90.2 98.7 99.1 95 89.7 94.9 97.2 98.7 98.8 98.3 97.1 97.9 97.6 89.5 86.7 96.3 89.1 92.2 95.5
Standardized Precipitation Index 1.88 1.29 2.21 2.38 1.65 1.27 1.64 1.92 2.22 2.27 2.12 1.9 2.04 1.98 1.26 1.11 1.78 1.23 1.42 1.7