The white dots in this photo are snowflakes. The tremendous changes in altitude in the Grand Canyon, over a mile, mean that the bottom of the canyon is desert and the rims of the canyon are in pine forests. The temperature differential can be more than 70 degrees in the same day from the Rim to the River. One day we started out on the North Rim at 6:30 am and the temperature was 28 degrees. By the time we reached Phantom Ranch on the Colorado River at 11:00 am the temperature was 97 degrees and went up from there. I like this photo of the Canyon because it isn't your standard view, but it is more like what you might expect, especially in the winter months, than the travel brochures would have you believe.