September marks the start of autumn.
Whether or not the cozy season speaks to you, it’s a popular time for domestic travel.
With kids back in school and the summer heat lifted, horizons seem to open up. That’s especially true for excursions into nature, as the blistering sunshine is traded for cool breezes.
That being said, autumn looks different depending on where you live.
Honolulu and Juno, for example, are worlds apart. The same is true for cities in the continental US, from Miami to Seattle.
When September comes, some travelers might actually be looking to escape the cold already. In other cases, they might be looking to escape the last grip of summer heat. Others might simply be in search of sunshine before the winter tightens its hold on the northern hemisphere.
In other words, September is one of the last times that travelers can find that ‘perfect’ temperature that they’re looking for. At least, while staying in the continental US.
Want to take a closer look at the coldest & warmest US cities in September?
Here are the top five cities in both categories.
5 warmest US cities in September
Phoenix, Arizona
The average temperature in Phoenix in September hovers around 90°F. That temperature can spike up to 95°F during warmer days before lowering into the mid-60s at night.
If you’re on the hunt for dry heat and endless sunshine (more on this below), Arizona should be on your list. Just make sure to bring the sunblock.
Tucson, Arizona
Like Phoenix, Tucson’s average temperature in September hovers around 90°F. Overall, the city faces fewer high-heat days than its Arizona counterpart. Still, visitors can expect high summer temperatures.
Thankfully, Tucson is sheltered by mountains, which offers visitors hiking trails to explore nature. Keep in mind that most people hike during the early morning or late evening to avoid high temperatures.
Riverside, California
Riverside doesn’t get quite as much attention as other Californian hotspots, but it’s a top-tier choice for travelers looking for heat in September.
Best of all, this inland location is a short drive from Los Angeles—not that locals would be experiencing a much cooler September. Like Tucson, Riverside is home to extensive hiking trails.
Sacramento, California
As a former resident of Sacramento, I can assure you that it’s still very warm in September. Like other inland and arid spots, it’s known for its dry heat and cool nights. Temperatures hover around 86°F on average throughout the month, but drop down into the 60s most nights.
Dallas, Texas
Everything is bigger in Texas, including temperatures. Along with Austin, Dallas is known for its lengthy summer—which extends into September.
However, it’s average temperature for the month is much lower than others on this list at around 85°F, making it a great escape for those who want to sample barbecue, listen to country music, and head to a rodeo in a never-ending summer.
5 coldest US cities in September
Billings, Montana
Billings is one of the top stops on the way to Yellowstone National Park. Given its location near the Rocky Mountains, Billings is an ideal stop for those who want to explore the rugged wilderness and escape the heat.
In September, temperatures average around 65°F. Plus, it’s one of the best locations int he Rockies to soak up fall foliage.
San Francisco, California
California residents have the best of both worlds. Those exhausted by the heat in Riverside and Sacramento need only drive a few hours north to San Francisco, one of the coolest and foggiest places in the US.
If you’re looking to explore an urban wonderland without breaking a sweat, then San Fran should be on your list. Temperatures average around 65°F in September.
Portland, Oregon
Not too far north from San Francisco, you can find another cool September escape. Following the summer, Portland’s temperatures swiftly drop.
In September, this quirky city averages a temperature of 67°F. It’s a great choice for those who want to balance outdoors activities with a great urban experience.
Seattle, Washington
In terms of cool temperatures, visitors can expect averages around 64°F in Seattle during September. Just keep in mind that these temperatures will likely feel lower thanks to humidity and moisture levels. And don’t forget to bing your umbrella. And a poncho. And rainboots.
Detroit, Michigan
Thanks to its location near the Great Lakes, Detroit has one of the US’s harshest winter seasons. But that’s not a problem in September.
During this month, temperatures hover around the mid-60s. This provides the perfect window to soak up the autumn displays around Michigan while exploring nature. Just make sure to do so before October’s cold front hits.