Race calendar · September 2027
22 marathons across the US in September 2027, sorted by date. Which weekends are busiest, what the fields actually run, entry fees, and where each one starts.
September marks the true start of the fall marathon season, but the country is not yet running in the same conditions. The South and low-elevation areas are still working through late-summer heat and humidity, while the Northern states and mountain venues have already shifted into the cooler, more stable air that makes 26.2 miles manageable.
For most runners, a September marathon is either a goal race earned through a full summer of training or a tune-up that sets the stage for a faster effort later in the fall. Either way, the calendar is narrow this month, so flexibility on location matters more than it will in October or November.
Course profile and start time carry extra weight in September. A shaded, lower-elevation route in a cool region is a very different race from an exposed course in a state still seeing summer temperatures. Check the race start time and the local forecast before you commit, not just the date and the entry fee.
What the field actually runs
How we calculate these stats: RunSesh calculates these figures from the most recent published results of past editions, sourced from RunSignup. We show aggregates only: field size, winning and median times, and the cutoff. We never publish individual finisher tables. Last updated Nov 12, 2026.
When in September
Marathons are not spread evenly across September. Here is how the calendar actually falls, weekend by weekend, which is the part worth knowing before you book a trip or plan a taper around one.
By the numbers
The September marathons that stand out on the numbers: the biggest field, and the longest unbroken run of editions.
It is a lean month for the Marathon. September carries 22, against 71 in April and 14 in August, the quietest. A September race is worth planning around rather than picking late, because the one that fits your training block may be the only one within reach.
It depends almost entirely on where the race is. Mountain and Northern venues can be cold at early-morning starts, making arm warmers or a light layer worth packing even if you shed them after mile two. Southern and low-elevation courses can still feel like midsummer at gun time, so moisture-wicking singlets and a hydration plan matter more than warmth.
In the right location, yes. Courses at elevation in cooler states offer conditions comparable to classic fall racing. Heat and humidity in warmer regions can add meaningful time to any effort, so the venue matters as much as the course flatness. If a qualifier attempt is the goal, prioritize start temperature and course exposure over convenience.
A standard marathon build runs roughly sixteen weeks, which puts the start of a September-race plan in late May or early June. That means your heaviest training weeks land in July and August, historically the hottest and most demanding period of the year. Building heat tolerance through summer long runs is not optional for a September finisher - it is part of the race preparation itself.
If your training is peaking now and you need a race, traveling is worth it. The small calendar means fewer crowded-start headaches and more direct communication with race organizers. If your only goal is options and you have flexibility, the fall calendar expands considerably once October arrives, and conditions are more uniformly reliable across the country by then.
The busiest weekend is September 4 and September 5, with 8 of them, 6 of those on Saturday, September 4. One more falls on a weekday, which is worth knowing if you are traveling for it.
Across the 14 of these September marathons with published results from past editions, the median finisher ran 4:15:47, and the median winning time was 2:47:47. So anything under 4:15:47 puts you in the faster half of a typical field. That is the middle of these RunSignup fields, walkers and charity entrants included, not a national average.
The median one finished 107 runners, across the 14 of these September marathons with published results from past editions. Most are far smaller than the big-city events people picture, which means less crowding at the start and a friendlier field, with a last recorded finisher at 6:48:08.
Idaho has 3, Florida has 2, Maine has 2, Oklahoma has 2, Washington has 2. If you are willing to travel, those are the states where a September weekend gives you the most to choose from.
Yes, 5 races around the United States get you off the pavement: 3 are trail races, and 2 mix road and trail.
