According to the Cheyenne Office of the National Weather Service, today is the first day of meteorological fall. If it seems like fall came unusually early, perhaps an explanation is in order.

The National Weather Service defines meteorological seasons--as opposed to calendar seasons--as follows:

Meteorologists and climatologists break the seasons down into groupings of three months based on the annual temperature cycle as well as our calendar. We generally think of winter as the coldest time of the year and summer as the warmest time of the year, with spring and fall being the transition seasons, and that is what the meteorological seasons are based on. Meteorological spring includes March, April, and May; meteorological summer includes June, July, and August; meteorological fall includes September, October, and November; and meteorological winter includes December, January, and February.

Image may contain: text that says 'First Day of Meteorological Fall! 77° Bill Highs Today 78° Casper 78° Douglas 75° Lusk 80° Chadron 76° Harrison 70° Shirley Basin 70° 80 Rawlins Medicine Bow 66° 70° Arlington 70° Saratoga Laramie 79° 80° 80° Garrett Wheatland Torrington 80° Alliance Scottsbluff 82° Bridgeport 73° Baggs Cheyenne Kimball Seasonably warm temperatures today across the area. Dry conditions are expected with mostly sunny skies. September 1st marks the first day of Meteorological Fall. 79° Sidney NATIONAL WEATHER SERVICE CHEYENNE WYOMING'