I live in Canada and while most folk just assume I'm Christian, nobody really cares once they find out I'm not. Thankfully I am judged more for who I am and what i do, rather than my beliefs (or lack there of).
I don't slag folks for being religious and I don't expect folks to slag me for not.

I live near the burg of saint Cleve Ohio and I never give it a thought, and someone asks I tell them. If they wish to try and convert me or save my soul, I ask them to go in peace and take their god with them.

Mostly Bible belt USA in my opinion. Keep in mind an old Merle Haggard song in which the mother is praying for her son's crops to fail. In other words, if you are not right with god your parents will pray anything for god to stop you and this includes taking away your livelihood. It's a bad take on the plagues of Egypt. Over time the parents will note whether you date women and how much it appears you pray. If you are not begging to say grace over the meal you might be called on it. Then you have to "come out" as the saying goes. People even today live this crap daily.

Really? Do you really think bible belt in USA is the worst place for atheists?
There are places in Africa or middle east that you can get death penalty if you abandon Islam or Christianity.

Even more places that you will be in deep trouble to keep your life going as the local organized religion provides a big part of the social services.

Expanding it even more, there are places where you will be guilty for every bad stuff that happens with your family because "of course your uncle that drinks a lot but goes to church every Sunday is only beating the shit out of his wife because the devil entered the family through you!"

Or the evangelical mobsters that are evicting and killing any non follower of their religion in some areas of Brazil.

Even countries that should be fairly westernized as Argentina, the president MUST be catholic, other american countries you can even find difficulties to find a job or be fired if you are not from some kind of christian religion.

And not even citing laws all around that gives special treatment if you re part of some religion.

Bible belt is not even close to be the worst place for an atheist.

Or by countries/regions you think only in the "part of the world that matters?"

I think it’s only the US.

I will never be able to come out publicly as atheist as it is punishable to be atheist in Afghanistan and disclose it, if I want to visit Afghanistan again in future.
It has been 6 years that I am atheist but till now only few of my close friends know about it, and my religious family still think that I am Muslim and whenever we talk on the phone, they repeatedly remind me not to forget the the daily prayer, and I just say, OK don't worry. lol

I guess I'm lucky in knowing who I am, religious free science birth.

It must be the Bible Belt only. Being athiest has been a complete non-issue for me my whole life living in Cincinnati OH and Lexington KY.

i live n florida, a weird state, if somebody asks me about anything religious my response is always MIND YOUR OWN BUSINESS!

I was lucky I could come out were I worked but I only knew of two other atheists. There was probably 1500 people in my factory. I think there had to be more but they chose to be quiet. I kind of enjoyed the discussions and it got heated sometime. Now I’m staying in China with probably 90% atheists. It’s seems to me they just don’t care and it’s not even worth talking about. My wife always says “what’s the big deal”. They are a different kind of atheist because there was no indoctrination.

Mostly bible belt but can be pervasive

i think gay people still have the same problem, and mostly in the same places, with the caveat for both groups that families vary too and one can live in a pretty liberal community and just your luck, your folks go weird on you.

g

I’m out and not quiet about it but have had several friends “confess” to not believing but didn’t feel comfortable coming out to friends and family. I’m in Minnesota

I'm out. Have been for decades. Everyone knows it.

No one, that I'm aware of, has cut me off from their kids.

It's been a REALLY long time since anyone has challenged me
about my atheism.
I always welcome the challenge, but I haven't been going out of
my way to cultivate confrontation either.
I'm just tired of jousting with delusional people.

Definitely other countries. Try Muslim countries where apostates can be killed, or Mormon and JW churches will turn your families against you. I live in the Bible Belt, and I'm afraid if I were honest that I'd hardly get to see my grandchildren. It's a scary thing for some of us.
I hate living "in the closet" but I don't feel like I have a choice right now.

Utah