Summer is officially over. Today is officially the first day of Fall. The National Weather Service in Flagstaff says you know when it’s fall in Northern Arizona when the average high temperature is 76 degrees and the average low is 36. High temperatures in Flagstaff are around the fall norms, however we have been above normal for the low. Fall also means the changing of the leaves up on the San Francisco Peaks and around Flagstaff. The fall season runs through Tuesday, December 21st.