Standardized Precipitation Index Table

San Joaquin Drainage Climate Division

California, Climate Division 05

Precipitation Data Table

Time Scale in Months (As of the end of Feb. 2026)
1 2 3 4 5 6 7 8 9 10 11 12 15 18 24 30 36 48 60 72
Accumulated Precipitation (in.) 4.03 6.68 10.42 15.18 17.23 17.77 17.93 17.96 17.98 18.13 19.04 23.42 29.74 32.36 38.71 51.95 62.28 89.47 103.01 117.14
Accumulated Precipitation Departure from Normal (in.) 0.57 -0.55 0.05 2.81 3.89 4.12 4.18 4.13 3.95 3.29 2.5 3.62 -0.44 -1.07 -0.87 -1.23 2.95 10.37 4.14 -1.54
Accumulated Precipitation Percent of Average 117 92 100 123 129 130 130 130 128 122 115 118 99 97 98 98 105 113 104 99
Accumulated Precipitation Percentile (non-exceedance) 67.8 52.4 56.4 74.5 79.4 80.7 80.9 80.7 79.8 76.3 71.3 75.9 51.2 47.8 48.7 47.7 63.2 81.2 63.7 47.4
Standardized Precipitation Index 0.46 0.06 0.16 0.66 0.82 0.87 0.88 0.87 0.83 0.72 0.56 0.7 0.03 -0.05 -0.03 -0.06 0.34 0.88 0.35 -0.07