I'm going out on a limb here to say that right about then would be an ideal time to just cut a loud fart and smile...

I would have most likely have replied that god had nothing to do with it. This would have upset her into a path of explaining how god controls everything including our weather. That conversation opens up a big door of ridiculous nonsense.

Yep is fine.....the end

If I were you, I would say, Thanks to the nature.

Your response was fine. There is so much nastiness around and not enough kindness. It doesn't sound like she was trying to force you to accept her beliefs. She was expressing gratitude for the beautiful day as she saw it. There is no need for anyone to be a jerk in situations like that. The ones who do are the ones who give atheists a bad name. I prefer to set a kinder example, but if that person does start to get pushy with the religious stuff, I will let them know I am a nonbeliever.
Around here, I feel bombarded with the "Have a Blessed Day!!" comment at every business I frequent. It seems that it has just been the last couple of years that it has started to be a constant thing. I always wonder if it is the individuals who are choosing to do that or are the businesses pandering and requiring their employees to use that phrase. It gets on my nerves, I have to admit. I always just look at them and say, "Have a good day yourself."

If I have the time I usually say "which god"?

I normally agree yes, but I also say thank the universe, or mother earth. I'm always greatful for all the beauty I find, so I can relate to the excitement and appreciation.

God has nothing to do with it, or anything for that matter. You did OK.

I recall a somewhat similar situation. I responded with " well, whatever is responsible, it's definitely good ".
In return , I got an odd glance - but they said nothing else. Popped their bubble I guess ...

I probably would not have responded to the comment at all. If interested in conversing with the god-obsessed, I try to redirect the topic. I it doesn't work, I either excuse myself from conversing or let them know I am not a believer. Usually the former.

I think we have to pick our battles. I had a woman offer to pray for my son. I didn't argue or even say I wad an atheist. I didn't know her.

Yep is the perfect response.

No response is necessary. If she preached at you, then a response might be good.

You can't go wrong with "It sure is a beautiful day" - just omitting the god part in the reply. "Yep" was probably even better.

I\ve had it happen on an elevator and it was a gorgeous day (I figure nerves played a part in that - some folks don't like enclosed spaces). Oh and once at a checkout - I was told to have a "Blessed Day" - that one just fried me - because I do not want to have a Blessed Day? But how do you even respond to that without causing conflict? I seem to remember looking startled and leaving without further words.

Thankfully it's not something common in New England.

If I ever find the perfect - non-conflict inducing comeback... I'll let you know. lol

I feel so sorry for you guys. I would literally freak if anyone said that to me. Even as a mental health professional, I would imagine they were unwell. It would be sooo weird in UK. It is far more likely that people start ranting about football or Brexit or brown people...to which I would not care about protecting their feelings!

I usually consider how much time and energy I want to invest, and what the return is going to be. In a case like this, very sure my response would be very like your own.

... Indeed ..

Yuppity-yup!

I think that’s the right way to handle it. No need to explain yourself to strangers or just go along with their wishes. Tbh if she had been anymore insistent than you described, I would’ve found a nice way to end the conversation. I won’t lie though, I have been rude to religious people who get too pushy. I understand they feel compelled to share their truth or whatever, but I have my personal limits and I don’t let anyone cross them.

“Well,” “I wouldn’t go that far”

I would've said yup or something, I let these people think that God has something to do with the weather. Most of us know that weather has to do cold and warm fronts and barometric pressure, simply put.

Normally I just don't respond. Like I never heard the question. Where I live it makes life easier.

I would have given the credit to the local weatherman.

Kind of sick of "letting it go".
I'm just going to start telling everyone who even mentions their stupid religious
beliefs, to keep their delusions to themselves.
I don't care if they're just trying to be "nice".
Their assumptions do not require my compliance.

The elderly lady did not specify WHICH god to thank. Zeus? Odin? Amon-Ra? Krishna? The Flying Spaghetti Monster? Is there a deity that is specifically in charge of nice weather or pleasant days? It's very confusing.