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.
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30-Year Hydroclimatic NormalsUpdated: Wednesday, Sep 16, 2026 07:31 AM CT