Forsythia and other early blooming shrubs often have some premature opening in autumn. It is because their flower buds have comparatively short dormancies.

When you notice that there are a number of them it is almost certainly weather-induced, likely favoring those with a propensity to early bloom. I have two Picea species pushing new growth right now, which is really very odd.

I noticed a couple of blooms on a quince yesterday.

What short dormancy?

Still using the air here.

Yes I’ve noticed some azaleas are starting to bloom as well...wonder if that will hurt them because winter is about to hit?

This is a really bad thing. Some rhododendrons like 'Cupcake' are already ruined for next year, the flowers have either opened or the buds or so swollen they will never survive winter. Forsythia is doing it too of course, though one cultivar seems more prone to it than others.

Ness some flowers will be lost in spring, but usually it won't hurt the plant. Unless you have a sudden cool-down to well below freezing.