weather in flagstaff in september
Check the Weather in Flagstaff, Arizona in September before you book your next holiday. This gives the best indication of the weather in September and includes figures for temperature, sunshine and rainfall.1  23Â°C max day temperature.heck the Weather in Flagstaff, Arizona in September before you book your next holiday. This gives the best indication of the weather in September and includes figures for temperature, sunshine and rainfall. 1  23Â°C max day temperature.