In most years much to my chagrin, I rarely see an orchard oriole in my backyard in September. However, some commence their migration in the middle of July. By late August, most of them are en route to, or have already arrived, in their winter home in a vast area ranging from Costa Rica southward to Columbia.
I agree with you, they seem to migrate earlier.
So many changes are taking place, it is difficult to adjust to them.