The leaves are turning. Pumpkin-spice-flavored-everything is appearing. You're wondering if you can get a boyfriend in time for Halloween so you can execute the perfect couples costume.
In case you don't have access to a calendar, internet, or any other life-forms, the above is typically how you can tell that fall is finally here.
Oh, and did I mention that your skin is dry. Gone are the days of oily summer skin, and brace yourself for the bone-dry cold.