“”””””Just note: Leaving windows open overnight is not recommended for those with ground-level rooms, as it poses a burglary risk.
External shading can make a significant difference. Where possible, consider using awnings, shutters, or even large potted plants positioned outside to reduce direct sunlight. Indoors, reflective window film or even a simple layer of cardboard placed behind curtains can help bounce heat away from the room.””””””
My advice is that if you are going to live somewhere a long time then take the trouble to make a change if the benefit will pay off, if you have a window that would be great for the night air but it is too risky to leave open, then spend the money for burglar bars for that one window, if you have useless windows that the sun hits but that you don’t need to see out of, then take the effort to block them off in a detailed well-done way and so on, if one thing will make a big difference, then make the effort to change that one thing, it isn’t just about saving money, it is about being more comfortable and less annoyed.
“… large potted plants positioned outside…”
In a previous home, I had some large windows in the back of the house that got a lot of sun in the summer. I put up large bamboo trellises and grew morning glories there. They grew up the trellis and pretty much blocked out the sun. When the fall came, I just laid them down, cut the twine and threw it all away.