Why do Americans always talk about the weather when they meet?

When people meet, it is important to say hello. In China, people usually ask "Have you eaten" and "Why are you going?" . And in our eyes, in the eyes of westerners, he will interpret these pleasantries as "you want to invite me to dinner" and "you want to see me." Because of this, they don't talk about it when they meet, but regard the weather as a greeting. Westerners like to talk about the weather because it never offends anyone.