A small USGS stream gaging station with an antenna on its roof under a cloudy evening sky
Photo credit

A USGS stream gaging station on the Minnesota River at Lac qui Parle Dam, Minnesota. Photo: Tony Webster, CC BY 2.0, via Wikimedia Commons

Check a river’s flow.

Search any USGS stream gauge by river or station name, by state, or near you. Each card shows the latest flow and how it compares with the normal range for today’s date; open a gauge for the full picture: trend, water temperature and what it means for trout, safety and the official NWS flood stage.

Flow rate checkerSwitch tool

Quick picks: our 2,852 waters by state

Each state opens its USGS gauges and our water pages there; a water opens the live cards for its gauges, or the NOAA tides for flats and surf.

Search covers 11,178 USGS stream gauges that reported discharge, gauge height or water temperature in the 183 days before 2026-10-23 (USGS series catalog); readings are fetched live when a gauge is shown.

Where these numbers come from

  • Discharge, gauge height, water temperature and water quality: U.S. Geological Survey readings (provisional, can be revised), cached for 15 minutes. Where USGS publishes a gauge’s flow only once a day, the latest daily mean is shown with its date.
  • Normal range: the 25th to 75th percentile of daily mean flow for the same calendar day over the gauge’s record (USGS daily statistics), classed as USGS does (hyswap).
  • Temperature guidance for trout quotes the gauge’s own state fish and wildlife agency; where we found none, it says so and quotes federal guidance (National Park Service, U.S. Fish and Wildlife Service). Cold-water safety quotes the NWS; dissolved oxygen and pH are read against EPA criteria. Each line names its source.
  • Flood stage and forecasts: the National Weather Service’s National Water Prediction Service and its Turn Around Don’t Drown guidance. Tides: NOAA Tides & Currents.

General guidance, not a fishing forecast, a safety guarantee or a statement about access. Planning a trip? The trip planner shows these readings on every day you fish a water.