Standardized Precipitation Index Table

Western Climate Division

Massachusetts, Climate Division 01

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.) 7.86 9.32 16.24 23.17 25.31 29.84 36.51 41.26 52.15 57.09 59.91 64.23 75.89 88.15 110.98 133.92 171.84 212.43 261.33 321.31
Accumulated Precipitation Departure from Normal (in.) 4 2.36 5.84 8.88 7.07 7.69 10.05 10.48 16.92 17.62 16.38 16.78 18.08 18.6 16.2 16.98 29.65 23.03 24.73 37.5
Accumulated Precipitation Percent of Average 204 134 156 162 139 135 138 134 148 145 138 135 131 127 117 115 121 112 110 113
Accumulated Precipitation Percentile (non-exceedance) 97.1 86.4 98.3 99.7 97.9 96.7 98.5 97.4 99.7 99.6 99.1 99.1 99.1 98.1 94.1 92.3 98.5 92.8 91 96.2
Standardized Precipitation Index 1.9 1.1 2.13 2.76 2.04 1.84 2.16 1.94 2.71 2.62 2.38 2.35 2.38 2.08 1.56 1.43 2.18 1.46 1.34 1.77