Statistical shading percentiles are calculated from period of record (POR) data, excluding the current water year. Percentile categories range from: minimum to 10th percentile , 10th - 30th , 30th - 70th , 70th - 90th , and 90th - maximum.
For more information visit:
30-Year Hydroclimatic NormalsUpdated: Tuesday, Sep 22, 2026 01:41 PM CT