KUSA — This coming Saturday - September 1 - marks the beginning of Meteorological Fall. It’s different than the fall that’s marked on your calendar.
Astronomical fall, or the Fall Equinox (the official start to fall), is determined by Earth’s position relative to the sun. It is set to happen on September 22.
Meteorological fall is different. It’s based on temperature trends. Meteorologists across the country divide the seasons into 3-month increments. Winter goes from December through February, Spring extends from March through May, Summer lasts from June to August, and Fall goes from September 1 through November 30. We’ve been looking at it this way since the early 1900s.
Unlike Astronomical Fall, Meteorological Fall always starts on the same date. That helps us keep more consistent records on the seasons.
As we head into Meteorological Fall, here’s a few things you can expect around the Denver area:
- Average temperatures dramatically cool down starting in the month of September. We go from an average high of 84 to an average high of 72. By the end of the season, the average high drops to 46.
- That first freeze is coming! Denver typically sees that by October 7.
- And we’ll also see our first snow. On average, that happens here by October 18.
- Fall is our transition season leading to the coldest months of the year. So get ready for some big changes ahead!