Ok to run a generator at night if no one is around?

I'm not familiar but here in NE Florida almost everywhere it's low wind, 4-8mph, and flat. Might be some scrub brush or palmetto bushes. I could ensure the generator is downwind/lower. I know CO is the same weight as air but tends to rise since the source is hot and hot air rises.

Seriously, don't people do this all the time without issue? Hurricanes, tornadoes, ice storms, I've read about people running gennies in their garage all night. Door open, of course.

It's a 4 cycle, if that matters.