The north rim of the Grand Canyon is about 1000 feet higher in elevation than the south rim and has significantly more annual precipitation – on average 11 more inches of rain and 84 more inches of snow. While the climate of south rim is desert, the north rim is sub-alpine, with “Spruce-fir forests characterized by Englemann spruce, blue spruce, Douglas fir, white fir, aspen, and mountain ash, along with several species of perennial grasses…” (Wikipedia)
Autumn was certainly present during our early October 2011 visit to the north rim.