Standardized Precipitation Index Table

All Climate Division

Rhode Island, Climate Division 01

Precipitation Data Table

Time Scale in Months (As of the end of May 2025)
1 2 3 4 5 6 7 8 9 10 11 12 15 18 24 30 36 48 60 72
Accumulated Precipitation (in.) 8.39 11.97 16.24 19.52 21.38 28.31 31.17 32.05 34.07 38.26 42.48 46.82 67.57 85.87 115.07 141.44 164.19 214.69 258.77 309.23
Accumulated Precipitation Departure from Normal (in.) 4.83 4.3 4.24 4.02 1.96 4.57 3.28 0.33 -1.39 -1.2 -0.39 0.5 9.28 15.85 22.43 25.21 25.39 29.83 27.97 32.49
Accumulated Precipitation Percent of Average 235 156 135 126 110 119 112 101 96 97 99 101 116 123 124 122 118 116 112 112
Accumulated Precipitation Percentile (non-exceedance) 98.9 94.4 89.6 87.3 71.2 85.4 76.2 54.7 42.6 44.3 49.6 54.8 88.2 96.2 97.8 98 96.9 96.8 93.7 94.1
Standardized Precipitation Index 2.29 1.59 1.26 1.14 0.56 1.05 0.71 0.12 -0.19 -0.14 -0.01 0.12 1.19 1.78 2.01 2.06 1.86 1.85 1.53 1.56