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8 Sep 2026
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Best of Mammoth

Written by: Sarah Hinds Friedl, a life-long athlete and Mammoth local

There’s something about Mammoth Lakes in September that makes people do crazy things, like sign up for a 102 mile bike ride or attempt California’s highest hill climb. It’s a month where the only people awake before dawn besides fishermen are runners. And if you get a chance to visit the natural hot springs, chances are, you’ll cross paths with someone who bagged a peak earlier that day.

So, why is September such a good time for sports here in Mammoth Lakes? And if you’re looking to challenge yourself, how can you get started?

In this piece:

  • Why is September in Mammoth a good month for athletes?

  • What athletic events take place in Mammoth

  • What to know about training in Mammoth Lakes in fall

  • Where to stay in Mammoth for your fall training

Why is September in Mammoth a good month for athletes?

Perfect temperatures

The beginning of September is when we start to notice things cooling off, but not so much that outdoor activities become unpleasant. In fact, the average temperature at the beginning of September is around 73°F and then dips to the mid- to low-60s by the start of October. 

Those temperatures, plus our dry climate, means that you’ll feel a lot more comfortable working up a sweat here than you would in most other parts of California at this time of year!

Long, sunny days

September tends to be a pretty dry part of the year, meaning that we get to enjoy crisp, sunny conditions for all of our long runs and bike rides. And, even though we can start to notice the days getting shorter, we still get 10 to 11 hours of daylight during the month of September. 

The changing leaves

We don’t have scientific proof, but we wouldn’t be surprised to learn that it’s easier to exercise when you’re looking at something pretty. And Mammoth in September is about as pretty as it gets. No matter if you’re on foot or watching the scenery whiz by you on your road bike, the aspens and cottonwoods are ready to cheer you on from the sidelines.


The high elevation training

Okay, this doesn’t actually have to do with the month of September, but it’s one of the reasons why athletes flock to Mammoth Lakes instead of other parts of California. The fact is, the perfect weather conditions plus the advantages of high altitude training makes our area a popular choice throughout the summer months.

Empty trails

Obviously, we love our visitors and are grateful that summers have become a place where families want to make memories and enjoy nature. But when we’re trying to get in a 20k trail run before lunch and have to keep stopping to let folks by on the trail, we long for the mass-exodus that happens around the end of summer. 

That’s not to say that Mammoth Lakes is totally desolate in September. Instead, you’ll be sharing the trails with other athletes, which can be great for motivation and making friends!

The “Winter is coming” mindset

Speaking of motivation, there’s something to be said about the mental push that comes with training in September. From here on out, it’s going to be harder to find that training spark (unless, of course, you like exercising in the cold and dark.) So September can feel like a great time to get in the last of your summer training goals before you find yourself stuck on a treadmill or stationary bike until Spring.

What athletic events take place in Mammoth?

Given how many benefits there are to training in Mammoth Lakes in September, it comes as no surprise that we’ve got plenty of organized athletic events to choose from, including:

Mammoth Gran Fondo

Saturday September 12

The Gran Fondo is an annual road cycling event with options for 42-, 70- and 102-mile routes. It’s friendly and physically challenging, and it’ll give you some of the best views of the Eastern Sierra. And if those distances feel unapproachable, keep in mind that e-bikes are welcome, with a few caveats. 

The Gran Fondo isn’t just a great way to enjoy a road ride with locals and visitors, it’s also a fundraiser for the Mammoth Mountain Community Fund! Your entry fee will be going towards athletic and education youth programs for Mammoth locals.

Mammoth Tuff & Buff

September 18 to 20

If off-road cycling is more your speed, then you might opt for the Mammoth Tuff over the Gran Fondo. This is more of a three-day bonding experience than a bike race, complete with a beer-centric fun run, concerts and live performances. But, don’t get it wrong. While there are some fun and games, this is at its core a challenging athletic event, with distances of 40, 70 or 90 miles (give or take a few yards) over mostly unpaved, remote terrain. 

Like the Gran Fondo, there is a charitable element to the Mammoth Tuff, with a raffle to benefit local educational programs as well as Mammoth Lakes Recreation and Mammoth Mountain Community Foundation.

Mammoth Trailfest

September 24 to 27

Mammoth Trailfest is a race deeply-rooted in our community, with the goal of fostering connections and making outdoor recreation fun and accessible for everyone. Like the Mammoth Tuff, this is a multi-day experience, featuring performances by local artists, motivational chats, and food offerings from our area’s favorite eateries. 

The race options sound intimidating: the shortest option being a 3k that covers a 2,400ft vertical, with longer options like the 26k, 50k, or astonishing Mammoth Triple, in which you cover 51 miles over the course of three days. But, the Mammoth Trailfest isn’t your normal race. With plenty of support and generous cutoff times, this event has a 97% finish rate. 

Mammoth Ultra

October 2 to 6

Okay okay, the Mammoth Ultra is technically in October, but it’s still one of our best early Autumn races in the area. Again, this one’s not for the faint of heart. The Mammoth Ultra is an over 218-miler, taking place over four days. But it’s also put on by the team behind the Mammoth Trailfest, so you can expect a great community vibe from your on-the-ground support crew.

What to know about training in Mammoth Lakes in fall

Whether you’re already signed up for a local event or are thinking about digging your running shoes out of the back of the closet, there are a few things you should know about training in Mammoth Lakes in fall:

Dress in layers

September is that weird time of year when nights can be quite chilly but that intense high elevation sunshine can still surprise you during the middle of the day. So, keep yourself comfortable throughout your training session by wearing layers and leaving some space in your pack for when you’re ready to shed the outer ones.

Don’t forget the bug spray

Even though mosquitoes will start disappearing this month, it’s still a good idea to wear repellant, especially if you’ll be training in marshy areas like Sky Meadows or around Hidden Lake.


Keep an eye on the sunset

Sadly, the days are getting shorter, and you’ll want to be aware of exactly how much sunlight you’ll have for your training session. Remember that regardless of when the official sunset is, temperatures will start dropping as early as mid-afternoon, especially in shaded areas like the Lakes Basin. 

Be aware of your surroundings

September is a fantastic time to see wildlife here in the Eastern Sierra, but it can complicate your training routine! It’s recommended not to wear headphones in both ears and take corners slowly so that you don’t find yourself face-to-snout with a bear or other wild animal.

Take it easy

Training at high altitude is tough no matter the time of year. So, even though you may be feeling the pressure to get in your last few runs or swimming sessions before winter, remember to listen to your body and don’t overdo it.

Mammoth Mountain Reservations is your home base for your September training!

There’s nothing better after a long training session than coming home to a warm, cozy, and comfortable space. We have condos throughout Mammoth Lakes that are the perfect home base for all of your outdoor adventures, such as:

Mammoth Ski & Racquet Club, Unit 105

1 BR - 1 Loft | 2 BA | 6 Guests