Race calendar · December 2026
28 ultramarathons across the US in December 2026, sorted by date. Which weekends are busiest, what the fields actually run, entry fees, and where each one starts.
December ultras in the United States are a creature of the Sun Belt. California, Florida, Georgia, and Texas anchor the calendar, and for good reason: milder temperatures, lower humidity than summer, and surfaces that are not frozen solid. If you are based in the Northeast or upper Midwest, this month likely means traveling south or west to race.
The holiday window complicates logistics in ways no other racing month does. Flights are expensive, volunteer rosters thin out, and crew members have competing family obligations. Book lodging and crew commitments early, and pick an event with a realistic backup plan if travel gets disrupted.
December days are the shortest of the year, which means almost any ultra distance will involve darkness, a headlamp, and a pace plan that accounts for night running. Aid-station strategy matters more than in summer: warm food, dry layers, and a pacer who knows the back half of the course can be the difference between finishing and dropping.
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 Oct 16, 2026.
When in December
Ultramarathons are not spread evenly across December. 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 largest field of any December Ultra, from the most recent published results.
It is one of the busier months. December carries 28 Ultra races, against 34 in April, which is the fullest month of the year. There is a real choice of dates here, with less competition for entries than the peak of the season.
Start with a moisture-wicking base layer and a wind-resistant shell you can stuff in a vest pocket once you warm up. Gloves and a buff matter most at the start and during any night miles. In the South, temperatures can swing sharply between midnight and mid-morning, so plan for at least two clothing changes at crew points.
A full summer of base building followed by a structured fall build puts you at the start line in good shape. That means committing in June or July at the latest. The practical complication is that your peak long runs will fall in October and November, when other races compete for your weekend legs, so plan your tune-up races carefully.
It depends on where you live. Runners in cold-weather states often find December the most practical time to chase a southern or coastal ultra, because conditions there are genuinely good for the distance. Holiday travel costs are real, but so is the alternative: waiting until spring means a longer training cycle through winter.
Short daylight is the factor most runners underestimate. A longer ultra will send you into the night regardless of your start time, so headlamp management, night pacing, and keeping crew accessible in the dark all become race-day skills. Cold snaps can arrive fast in even mild regions, and wet conditions overnight are harder to shake than afternoon heat.
The busiest weekend is December 5 and December 6, with 8 of them. Another 8 fall on a weekday, which is worth knowing if you are traveling for one.
Across the 10 of these December ultramarathons with published results from past editions, the median finisher ran 7:30:10, and the median winning time was 4:37:16. So anything under 7:30:10 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 69 runners, across the 10 of these December ultramarathons 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 12:03:30.
Georgia has 7, California has 3, Florida has 3, Texas has 3, Virginia has 2. If you are willing to travel, those are the states where a December weekend gives you the most to choose from.
Yes, 5 races around the United States get you off the pavement: 5 are trail races.
