Today is the first official day of autumn, though it has felt like fall for a few weeks already. Autumn officially begins at the September Equinox, which is the moment the sun is directly overhead of the Equator. The earth doesn`t have a tilt from the sun on this day, thus marking the change from a 'forward' tilt (summer) to a 'backward' tilt (winter).
This event changes from year to year, usually happening September 22 or 23. According to the Farmers` Almanac the seasons will switch at 11:09 p.m. EDT on September 22.
The Farmers` Almanac also predicts a cooler September for the prairie provinces (Alberta, Saskatchewan and Manitoba), a warmer than usual October and heavy snowfalls beginning in November.