Autumnal Equinox

On my iPhone, I have various cities around the globe that I've been to, or want to go to, on the weather app. I've been noticing that most of the cities are in the 65-80 degree range lately. Today, that was true for all the cities but my own: Seattle. It was supposed to be 91 today, but I think it only made it to 86 or so. We've really had a warm, sunny summer/early autumn. Wonder how long it will last?