Here's Why We're Primed for a 'Fake Fall' This Year—and What's Really Going On

It happens almost every year—after a hot, sunny summer, a week or two of cool weather moves in at the end of August, or for the first part of September. And as pumpkin spice lattes start to pop up and Halloween decor appears in stores, you might be fooled into thinking that fall weather has finally arrived.

Inevitably, though, summer temperatures always seem to come back just as you’re pulling fall sweaters out of storage. Known as a fake or false fall, the temperature dip is only temporary, followed by the last few weeks of summer (or “second summer”).

Here’s why you might end up getting fooled by false fall and why Mother Nature tends to play a temperature trick during the transition between seasons.

What Is False Fall?

If cooler temperatures arrive sooner than usual, it could be a sign of an early fall.

“False fall to me is when we get a cool down around or just before the start of meteorological fall (September 1st),” says Paul Pastelok, lead long-range forecaster and senior meteorologist for AccuWeather. “If there are warm periods during September, then this period in late August can be deceptive on the arrival of fall.”

It’s called a false or fake fall because after the cool-down, temperatures return to typical summer weather. Depending on where you live, you might experience a few more weeks of warm summer weather before temperatures start consistently dropping, signaling the arrival of fall.

However, “average” temperatures can vary widely by location; it might be normal to see cooler temperatures arrive earlier in the northern parts of the country. At the same time, other states may have warmer weather year-round.

What Causes Fake Fall?

Though they can be deceptive at the end of summer, a short period of cooler temperatures isn’t uncommon.

“During the late summer, daytime heating is beginning to lose its punch across the United States, and that allows periodic intrusions of cooler air from Canada,” says Jonathan Belles, senior digital meteorologist for The Weather Company. “These can last a day or two, and their longevity grows through the autumn until there is only cool weather leftover.”

While a cold front can occur at any point during summer, it’s more likely to happen during the transition between seasons, or right around the time of “false” fall.

“For fall in the northern hemisphere, the ocean waters are peaking in temperatures and the daylight hours are starting to shorten, quicker near the poles,” Pastelok says. “This combination can lead to falling temperature averages, strong contrasts, and stronger cold fronts compared to mid-summer.”

Lack of Rain

A lack of rain in your area can also drive false fall temperatures. This year, with several regions experiencing droughts, it may increase the chances of a fake fall if your area is behind on rainfall.

“In areas that are in drought at this time of year, or going into extended dry periods, the nights tend to be cooler than expected, Pastelok says. “The dryness, low humidity, and longer nights allow temperatures to fall quickly and longer.”

False fall also isn’t limited to the colder weather that typically arrives in August and September. You might feel like you’ve been fooled by a fake fall if temperatures start to drop like usual, then unexpectedly heat up in October.

“You can definitely have warmer intrusions fight their way northward during October and November,” Belles says.

Knowing the Difference Between Fake and Real Fall

While fall officially begins on September 22 this year, meteorological fall is based on an average of annual temperatures and takes place from September 1 through November 30. Defining the true “start” of fall can also change depending on where you live.

“Real fall can be defined several different ways, and most of them are by feeling rather than a hard and fast rule,” Belles says. “Many would define the arrival of real fall as the first big cold front that sweeps through your region. In the south, the feeling of fall often begins when the last of the truly humid weather passes. In the north, it is the last 70 or 80-degree day.”

Some parts of the country are also experiencing a slight increase in average fall temperatures, which can make it more challenging to determine when “real” fall officially begins.

“There is a trend toward milder falls, Pastelok says. “Last fall, 2024, was tied with 2016 for the warmest fall on record.”

Turning Leaves

Paired with drought conditions, this might mean your area is more likely to see a false fall this year. But even watching the leaves turn isn’t necessarily a reliable indicator of when fall arrives. Rather than temperature, Belles says shorter daylight hours and lower sun angles actually have the most significant impact on when leaves start to change color.

Weather makes up a smaller portion of the reason that leaves change, but drought and freezes definitely have an impact on vegetation,” Belles says. “A long-standing drought from the summer months will cause vegetation to turn brown and orange earlier, while a wet summer and fall could keep leaves green longer.”

And after the leaves fall, you might still notice slightly warmer temperatures even once autumn has definitely arrived. “Watch when the leaves fall completely to the ground,” Pastelok says. “There tends to be a warm-up in northern latitudes around that time since the amount of shade disappears with the lack of leaves.”