Sometimes you read a book or see a movie where the setting, be it a house or a climate, is integral to the story. Any other choice would change the feel of the book, losing impact and possibly the reader. Lost Horizon by James Hilton is a great example of the world as a character. Set
Remember Mood Rings? Back in the 70’s we were entranced with the thermal sensitive stone set in a simple gold or silver ring (most of which turned your finger green). According to the color chart, when worn on the finger, the stone reacted to body temperature and changed color. I remember mine usually being black.
Every time we sit down to write fiction, we are worldbuilding. The term often brings the Science Fiction/Fantasy genre to mind but I know that in my genre, Romantic Suspense, I create worlds also. In my current book, SHARK BAIT, I created Belton Bay. It’s a nice little town on the coast of South Carolina.