Grand Canyon, Colorado River water temperature
This answer used to be easy. Due to the dam, the Colorado River through the Grand Canyon water temperature was pretty much a steady 50 degrees, more or less, year-round. Below is the average monthly data as recorded by the USGS from 1983 to 2003.
- January: 48.92 degrees
- February: 48.2 degrees
- March: 50 degrees
- April: 51.26 degrees
- May: 52.6 degrees
- June: 53.6 degrees
- July: 54.68 degrees
- August: 54.5 degrees
- September: 54.86 degrees
- October: 53.06 degrees
- November: 51.26 degrees
- December: 49.82 degrees
And then the water level in Lake Powell started dropping. This drop in lake level and subsequent lower river flows has meant that the water temperature has been quite a bit different lately, even cresting 65 degrees Fahrenheit. Below is a graph of January 1, 2023 to December 31, 2023.
What should you expect for your upcoming Grand Canyon trip? Your best bet for estimating water temperatures for an upcoming Grand Canyon trip is to use this tool, select the trailing 30 days, and for the parameter check “Water Temperature”.
Further reading: The Glen Canyon Dam Active Management Plan Wiki has a wealth of knowledge on Grand Canyon river temperature
The timing of seasonally warm release temperatures and high summer air temperatures have a large influence on downstream river temperatures. The warmest release temperatures occur in late October/early November but the greatest potential of warming the river in Grand Canyon occurs in July and September when air temperatures are the hottest. The reason is that it takes a lot longer to warm all the water in Lake Powell vs the water in the river as it flows downstream through the canyon.
Another thing to note that during the winter, river temperatures actually cool with distance downstream because releases are actually warmer than ambient air temperatures.Glen Canyon Dam AMP