Yes, does go into estrous at approximately the same time each year, regardless of any other factors. It usually falls within a couple days of the previous year. They will recycle every 28 days until they are bred. Cold weather has nothing to do with the timing of the rut. Cold weather IS however, the single most important factor at initiating deer movement. The rut is going to occur every year at the same time. People's perceptions are that it changes annually because of what they observe in deer behavior. Cooler temps = more deer movement in day light. Warmer temps = less deer movement in day light. They're breeding whether it's warm or cold, and when you're not observing it due to warm weather, it's still taking place.