Standardized Precipitation Index Table

Northwest Plateau Climate Division

Pennsylvania, Climate Division 10

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.) 5.81 10.3 12.48 15.9 17.5 20.91 24.48 26.55 30.08 35.26 38.06 42.28 56.21 66.17 88.16 106.44 129.48 182.01 217.8 269.86
Accumulated Precipitation Departure from Normal (in.) 1.85 2.68 1.5 2.36 0.85 0.99 1.13 -0.3 -0.46 0.91 -0.67 -0.81 2.15 3.11 1.92 0.25 0.1 9.48 2.18 11.03
Accumulated Precipitation Percent of Average 147 135 114 117 105 105 105 99 98 103 98 98 104 105 102 100 100 105 101 104
Accumulated Precipitation Percentile (non-exceedance) 88.9 90.2 75.2 81.8 63.7 64.9 65.3 48.5 46.9 60.1 46.1 45.3 66.1 71.1 61 52.3 51.4 79.3 57.2 76.7
Standardized Precipitation Index 1.22 1.29 0.68 0.91 0.35 0.38 0.39 -0.04 -0.08 0.26 -0.1 -0.12 0.41 0.56 0.28 0.06 0.04 0.82 0.18 0.73