"Atsui desu, ne?" (It's hot, isn't it?) This is the universal summer greeting in Japan. You can be in a crowd of complete strangers when someone will sidle up to you and, as an "ice-breaker," say, "It's hot today, isn't it?" And you agree with, "So desu ne." (Yes, it is).
Since everyone knows the "Atsui desu, ne" greeting anyway, we could make the process a lot simpler by just giving the answer first. Wouldn't it be easier to greet each other with "So desu, ne?"
But there is much more behind "atsui desu, ne" than merely its annoying ubiquity and the fact that "It's scorching hot today, and I feel like I'm going to burst into flames any moment" would be far more appropriate.