Share of ranked gages below normal, by state
Below normal = under the 25th percentile for the date. States with fewer than 10 ranked gages are left out. Full table: latest.csv.
| state | ranked gages | below normal | below 10th pct. | above normal |
|---|
About
USGS WaterWatch published these maps until it was retired on 2026-02-26. This page recomputes them every night from USGS daily discharge with the same rules: the n-day mean flow ending on the date is ranked against the n-day means ending on the same day of the year in all other years of record, and only gages with at least 30 such years are ranked. Checked against WaterWatch's own archived 7-day maps (823 gages on six dates, April 2025 to February 2026): same class for 91%, within one class for 99%; outside the two winter dates, 94% and 99.9%.
- Recent values are provisional and change as USGS reviews them. Ice-affected winter days are often missing until USGS estimates them, so many northern gages go unranked in winter, as they did on WaterWatch.
- Regulated rivers are shown as measured.
- Gages: those in the basin table that ships with USGS's hyswap package (conterminous US).
Data and code: github.com/zer0contextlost/waterwatch-runoff · watershed runoff 1900-2026: Hugging Face. Not affiliated with or endorsed by the U.S. Geological Survey.