Standardized Precipitation Index Table

Southwest Climate Division

Arizona, Climate Division 05

Precipitation Data Table

Time Scale in Months (As of the end of Nov. 2025)
1 2 3 4 5 6 7 8 9 10 11 12 15 18 24 30 36 48 60 72
Accumulated Precipitation (in.) 1.67 2.42 3.98 5.18 5.23 5.39 5.58 5.62 6.12 6.16 6.17 6.17 6.24 6.54 10.38 12.78 15.41 20.07 25 29.3
Accumulated Precipitation Departure from Normal (in.) 1.23 1.68 2.76 3.08 2.58 2.71 2.85 2.73 2.78 2.22 1.59 0.96 -0.16 -1.33 -0.05 -0.32 -0.23 -0.81 -1.14 -2.12
Accumulated Precipitation Percent of Average 379 328 327 247 197 201 205 195 183 156 135 118 98 83 100 98 99 96 96 93
Accumulated Precipitation Percentile (non-exceedance) 97.6 96.8 98.4 97.9 95.5 96.1 96.5 96.2 96.4 90.9 82.4 72 52.2 32.4 53 49.4 50.5 44.9 42.8 36.1
Standardized Precipitation Index 1.98 1.85 2.16 2.04 1.7 1.76 1.82 1.77 1.79 1.33 0.93 0.58 0.05 -0.46 0.08 -0.01 0.01 -0.13 -0.18 -0.35