That's a loaded question.
Are they capped, then you can pull them.
For us in the South, our best time is when the supers are capped and while the flow is still on. If you have the only hive within miles then any time. If there is no flow, robbing starts almost immediately and gets really bad especially when you have hundreds of commercial hives right on top of you like I do. Last year I could hardly remove 2 boxes and I would have to stop and turn on the sprinklers to stop the robbing. That makes it very hard to remove supers with 12 hives. It took 2 days. This year, we are waiting until they remove the commercial hives which was last night.
Michael Bush, in Nebraska, waits until winter to pull honey. He waits until the bees are in cluster in the brood box. This allows him to determine hive size and how much honey he needs to leave for the bees. By doing it this way, he doesn't have to clear the bees out of the supers.
Jim