Of course by now (1 day til October!) there would be no question it's acceptable, but if you're dying to "spook" your house early again next year then I'd say go for it!
Many people consider the start of September* to be the official start of fall - which we all know is just another word for Halloween! ;-) There will be plenty of people who will love seeing the slightly-early decorations.
*When I'm guessing this was posted, as it just shows "4 weeks ago" to me.