These data were compiled to assess the physical attributes of the Colorado River and its tributaries in Grand Canyon, including discharge, water temperature, Annual Thermal Units, and the potential future thermal regime of the river due to climate change. The objective of our study was to assess whether this river reach could support various life stages of Colorado pikeminnow (Ptychocheilus lucius). These data represent discharge and water temperature in the river segment between Glen Canyon Dam and the Lake Mead inflow, as well as data from Lake Powell that drive water temperatures in Grand Canyon. These data were collected in the Colorado River in Grand Canyon from 1/1/1950 to 9/8/2021. These data were collected by the U.S. Geological Survey (discharge, water temperature, Lake Powell thermal profiles) and the Bureau of Reclamation (Lake Powell thermal profiles, reservoir surface elevation). These data were collected via field observation or by USGS stream gages. These data can be used to understand how discharge, water temperature, and changes in the elevation of Lake Powell affect the physical attributes of the river downstream from Glen Canyon Dam in order to evaluate habitat suitability of the reach for Colorado pikeminnow.