DENVER (KDVR) — Fall is almost upon us, or is it? As with many things, the answer depends on who you ask.
If you’re a huge fan of the season, you might start breaking out those sweaters and scarves as soon as possible. However, not everyone wants summer to end.
While there isn’t a perfect consensus on the exact day you can start to enjoy the pumpkins and the leaves, FOX31 compiled a list of a few dates that are accepted by many as marking the official “start” of the season.
When is the first day of meteorological fall?
As the name suggests, meteorological seasons are based on the weather and climate, according to the National Oceanic and Atmospheric Administration.
Essentially, with 12 months in a year, the seasons are broken up into four three-month groups:
- Winter: December, January, February
- Spring: March, April, May
- Summer: June, July, August
- Fall: September, October, November
That means that Aug. 31 marks the official end of summer and Sept. 1 as the first day fall, at least meteorologically.
Along with spring, fall is a “transitional” season, when the weather gradually goes from one extreme to the next. In fall’s case, that means a gradual decline in temperatures until we hit winter.
Astronomical fall (fall equinox)
Astronomical seasons are based on the position of the sun in relation to Earth. Specifically, each season starts when either the solstice or equinox of that season hits.
For fall, that start is the fall equinox, which happens Sept. 23 this year. That is the day when the sun passes directly above the equator, and when day and night are equal to each other.
After that, days gradually start to get shorter and nights longer until the winter solstice on Dec. 21.
When the leaves change
Likely the most obvious sign of fall — and the reason the season is known to many as “fall” to begin with — are the autumn leaf colors.
Essentially, as temperatures start to decline, the leaves of many trees begin to change colors before eventually falling.
FOX31 talked to a certified arborist at SavATrree, Johnathan Raleigh, who said temperatures have to dip below 85 degrees for five consecutive days for leaves to start changing. However, the peak season for fall foliage in this area is typically September or October.
When the first freeze happens
Because weather can change a lot from year to year, the most you hope for ahead of the actual first freeze is an average day based on the past.
On average, Denver sees its first freeze around Oct. 7, according to the National Weather Service.
If you just look at the last 10 years, there’s quite a lot of variation there. For example, Denver saw its earliest-ever freeze on Sept. 8, 2020. However, five years earlier in 2015, the ninth-latest freeze was recorded on Oct. 28.
Cultural fall
The other ways are relatively objective — there isn’t a lot of debate on just what day the fall equinox is — however, culturally, what people think of as “the start of fall” varies.
Starbucks started selling its iconic Pumpkin Spice Latte on Aug. 24. For some, the availability of that drink is the best barometer for the season change.
Some of the most popular fall events in the Denver metro area start happening in September and October, and for many, that’s the real start to the season.
