My father always said that, in the fall, you should make a note of the first day you observe a large group of blackbirds. Add six weeks to this date, and you get the date of first frost in your area.

I think I've chronicled this in various posts here over the last few years....and it's remarkably accurate.

BTW - "No, no, no, no, I don't smoke it no more...." (Actually never did!)