Everywhere has 3 ruts as does come into estrus every 21 days and are only available for breeding within a short window. It is natures way to ensure as many available females are bred. Length of daylight start off the primary rut (1st and most intense breeding period) then the estrus calender takes over for successive ruts.

Weather has absolutelty nothing to do with the rut, though it has everything to do with seeing the activity of the rut. The reason for daylight is stable year to year (unlike weather, moon phases, etc). Without such; if bred early they may be born in harsh conditions, if bred to late they don't have enough time to develop survival skills. Nature is very proficent everything happens for a reason and in cycles to promote survival of the species.