Hi,
NY Bowhunter is right. The shortening of daylight triggers the rut and it is not affected by temperature. However, warm days make deer activity less, so it seems as though the rut is not on, and they move more at night. But a sudden cold snap will spike deer activity and you will see more deer, that' s what has led many hunters to conclude that temperature affects the rut.
Good Luck this Season!
Mark
http://www.buckhuntersecrets.com