The brownish tips? That's fungal damage. What's your closest city? In what state? Are you watering? Is this a new lawn? Do you know the grass type? Have you fed the lawn? Other than these areas, how widespread is this?

Yes the brown tips. I’m right outside of Chicago Illinois. Yeah I was water. Not as much as it got colder. Haven’t in a couple weeks. It’s not a new lawn and I’m not sure the type of grass. I did a liquid fertilizer a few weeks ago. There are probably 10ish spots in the backyard.

Fungus, then, at this point combined with dormancy as the lawn gets colder. In a northern mix lawn as that's what's going to survive in Chicagoland, IL, and what you have if you're not sure what you have there. :-)

It could be brown patch or half a dozen other things. It's hard to tell when the weather already took it out for you, at least temporarily. The spores are probably still there, but it's hard to kill the spores and you're not going to do much about them with any fungicide in November.

I wouldn't do anything about this at this time as temperatures are falling too far for most summer and fall fungi in that region to last much longer. You can fertilize one last time now if you want--with a good granular nitrogen heavy fertilizer--or let it go if you prefer.

But keep an eye on those patches in spring and summer.

While I can't tell what kind of fungus it was, it's likely to rear its ugly head again when the weather warms back into the same range it flourished in during late summer and fall if it's going to come back.