Standardized Precipitation Index Table

Northwest Plateau Climate Division

Pennsylvania, Climate Division 10

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.) 6.08 10.93 11.87 14.39 17.81 20.94 25.78 28.18 30.11 32.56 38.23 44.31 54.41 62.99 84.69 106.77 128.61 172.62 223.94 259.93
Accumulated Precipitation Departure from Normal (in.) 2.4 3.87 2.27 1.69 1.85 1.55 2.88 1.6 -0.27 -2.18 -0.88 1.24 1.75 0.48 -1.51 1.11 -0.75 0.11 8.27 1.12
Accumulated Precipitation Percent of Average 165 155 124 113 112 108 113 106 99 94 98 103 103 101 98 101 99 100 104 100
Accumulated Precipitation Percentile (non-exceedance) 95.5 97.2 85.6 76.5 77 71.8 81.8 68.7 48.9 33.1 44.4 61 63.6 54.5 43.1 56.5 47.9 51.3 73.1 53.7
Standardized Precipitation Index 1.69 1.91 1.06 0.72 0.74 0.58 0.91 0.49 -0.03 -0.44 -0.14 0.28 0.35 0.11 -0.17 0.16 -0.05 0.03 0.62 0.09