The Madison Thermal Decision Support System (DSS) is developed, updated and maintained by Northwestern Energy to manage water temperature downstream of Madison Dam to protect resident fisheries and related river resources by optimization of upstream hydropower operations as required by our Federal Energy Regulatory Commission (FERC) license. The goal of the DSS is to maintain maximum daily water temperature in the lower Madison River (near Black‚Äôs Ford) at or below 80 °F. The DSS monitors air and water temperature, weather forecasts, and employs pulse flows from Madison Dam whenever lower Madison River temperatures are predicted to exceed 80 °F at the Sloan Meteorological Station (Sloan Met Station).

The information gathered from various sources, is made available to provide immediate access for interested agencies and public. While this information is generally reliable, human mechanical or other computational errors remain a possibility. Terms and Conditions for the use of this site and the data can be found at:

NWE promotes responsible recreational use at our projects.

For more information on preventing the spread of aquatic invasive species, visit
Montana Fish, Wildlife & Parks: