Fall in the North Rim of the Grand Canyon can start as early as September 20 and as late as the first week in October, depending on the year. The days can warm but the nights can be cold. Many of the aspens are yellow in color but many can be an orange or red if enough rain fell during the year. If conditions are right the fall can be spectaclar with aspen going from yellow to red among the conifers. There are a very few view points in which you can see color and the canyon.