As others have said, nothing is late. Bulls rutting is triggered by cows coming into estrus. Weather only effects animal movements, not the actual rutting.
So the rut happens precisely the same time period every year?
For some reason, we couldn’t get elk to talk until the very end of archery and now into the start of muzzleloader.
Most years, that hasn’t been the case and by muzzleloader they have quieted down a lot.
I don’t know the exact science. I know my observations (25 years worth), suggest rut activity is higher right now than it typically is this time of year when I’m in the woods.
cows come into estrus based on the amount of daylight entering their eye (according to people that study that stuff). So yeah, it's more or less the same time every year. Every cow is different as well. Mature cows will typically come into estrus sooner than younger cows. Often as early as late Aug. They've been bugging good in most of the yakima and Kittitas gmu's for a month now.