Spot seeding ?
I believe you can do that safely but you need to get right on it. Also you should plant perennial rye grass. That will germinate in 4-5 days.

Scrape / rough the bare areas. Put down compost or some top soil . Seed and then topp off with peat moss. Moisten the area 2x a day.

Don't mow over that area for a couple of weeks until the sprouts are 2-3" long. Grass I planted into bare areas 10 days ago is up and almost ready for mowing.

Generally can seed until mid Oct. then it's pushing it and the new grass won't harden before winter.

 

Since our octobers are much like what our september temps used to be, I think your good. The problem is the diminishing light. Get some rye down quick.

 

The problem is the diminishing light.

This is a vital part of plant growth and is often forgotten about.

Many will talk about air temps being steady through the end of October but neglect to think about sunlight.

I'd get seed down ASAP; either perennial rye or TTTF.

 

yes, spot seeding.
I have a large bag of vigoro tall fescue, from depot.
and a small bag of vigoro sun/shade mix from depot, which is kyb/fescue/rye blend i think.

should I buy a small bag of "contractor" type seed, which i assume is rye ?

 

Put down the tall fescue especially if it's a full sun area. Coastal CT you should be fine the fall season is longer but get it down ASAP. PRG would work better if you want to go buy some super quick germination and maturity

 

Contractor mix might have annual rye. Go with the fescue.