The Madison River flows can vary day to day, and season to season. Typically the Madison River flows are at their highest during the spring runoff, when the snow melts and water is rapidly released from Hebgen Dam and Ennis Lake. The length and severity of the spring runoff is determined by the snowpack each year. One thing for certain, fishing during the runoff does not suck. Don't be fooled by this misconception. The lowest flows on the Madison River are experienced in the late summer and dead of winter. Flows under 900 CFS can make for some skinny water, but nonetheless, the Madison River stays floatable year-round.
The river is rising thanks to input from the tributaries. It's colored it up a bit, but solid fishing has been reported by many different sources floating from Lyons all the way to Ennis Lake.
Upper Madison River Flows near Cameron, MT
Upper Madison River Water Temperature near Cameron, MT
Lower Madison River Flows below Ennis Lake Near Mcallister, MT
Lower Madison River Water Temperature below Ennis Lake
More information on the Madison River