I think what you experienced is that there are migratory hummingbirds that you have read about or that may come through your area, then you also have the ones that are not migratory and are native to that area, or at least don't migrate as far.
I had my feeders up all through October and November, but saw no sign of the birds for those two months, so I took them down for the winter. Time to put them back up!
