Black oxide is a finish applied to iron and steel. There is also a ' black oxide' process applied to the copper inner layers of printed circuit boards, but that is another topic.
Since Fall begins at the end of September (usually September 22nd) and ends at the end of December (usually December 21st), it seems much more logical to say that October through December are considered Fall months instead of September through November. Views.
Of course given the tendency for warmer temperatures, it's also a time when marshes created from snowmelt become breeding grounds for swarms of mosquitoes exacerbated by heaps of wasps (especially in the north). In Autumn (late September through early December), you can experience fall foliage.