Hi,
Local genetics and chance affect the timing of the rut slightly as well. And just like humans, does go into heat at different times in different areas also. This isn' t an exact science and does not work the same everywhere at exactly the same time.
If a doe goes into heat a little early in an area, the bucks will respond, and this will create a local early rut. But just because it happens to coincide with a local cold snap doesn' t mean that that' s the reason for it.
Mark
http://www.buckhuntersecrets.com