Is September a good month for a 5K?
It is one of the thinnest months of the year for the 5K. September carries 302, against 2,212 in November. Expect to book earlier and travel further, and start from the states below rather than from a date.
Race calendar · September 2027
5K Races in September 2027
302 5K races 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 is the hinge month for 5K racing in the United States. The Northeast and Midwest shake off summer sluggishness and return to brisk, fast conditions, while the South and Gulf Coast are still contending with heat and humidity that can turn a 3.1-mile effort into a grind. Know your region before you pick a goal time.
For most runners, a September 5K serves a specific purpose: sharpening speed after a summer base-building block, testing fitness before heavier fall racing, or simply marking the return of the road-race calendar. The distance is short enough that a bad weather day rarely ruins a result, but September's regional variability means race-morning conditions can swing dramatically depending on where you line up.
Daylight is still generous early in the month and shortens noticeably by late September, so evening races at the end of the month may run into dusk. Check start times and bring a layer for the finish, especially if you are racing in the mountains or the northern tier, where temperatures can drop fast once the sun goes down.
What the field actually runs
September 5K Races, By the Numbers
36:37Median finish time
19:21Median winning time
100Median field size
191September 5K races with published results
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
The September Race Weekends
5K races 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 Biggest and Longest-Running
The September 5K races that stand out on the numbers: the biggest field, and the longest unbroken run of editions.
September 5K Races by State
Texas 31Florida 24Georgia 13Illinois 12Michigan 12Pennsylvania 12California 11Colorado 11North Carolina 11Ohio 11Virginia 10Arkansas 9Indiana 9Oklahoma 9Tennessee 9New York 8Wisconsin 8New Jersey 7Kentucky 6Maryland 6Missouri 6Iowa 5Kansas 5Oregon 5South Carolina 5Arizona 4Maine 4Massachusetts 4New Mexico 4Connecticut 3Idaho 3Minnesota 3Washington 3Alabama 2Montana 2Nebraska 2Nevada 2New Hampshire 2Utah 2Delaware 1District of Columbia 1Hawaii 1Louisiana 1Rhode Island 1Vermont 1West Virginia 1
5K Runs by City in September
The Next 5K Runs in September
302 total Wed, Sep 1, 20272027 Suicide Prevention Color Walk/Run Center, COFrom $25Details Wed, Sep 1, 2027RSU Test Race 2 Flint, MIFrom $5Register Fri, Sep 3, 2027DeBary 50K, Marathon, Half, 10K & 5K DeBary, FLFrom $35Details Sat, Sep 4, 202725th Randall's Run/Walk for the Gym 5K SPRINGVALE, MEFrom $25Details Sat, Sep 4, 20272026 Good Shepherd Catholic Church International Festival 5K & Fun Run Alexandria, VARegistration opens Jun 24, 2027From $30Details Sat, Sep 4, 2027Leave No Trace Peninsula, OHFrom $30Details Sat, Sep 4, 2027Bampa's House 5K Run/Walk Painted Post, NYRegistration opens May 3, 2027From $30Details Sat, Sep 4, 2027Cow Chip Classic Run/Walk Prairie Du Sac, WIRegistration opens Feb 4, 2027From $30Details Sat, Sep 4, 2027Charleston Distance Run Charleston, WVFrom $25Details Sat, Sep 4, 202727th Annual Pocatello Marathon Pocatello, IDFrom $25Details Sat, Sep 4, 2027East Canyon Marathon - 26.2 - 13.1 - 10K - 5K Morgan, UTFrom $40Details Sat, Sep 4, 2027Step Up Half Marathon, Relay & 5k Storm Lake, IAFrom $25Details
Common Questions About Running a September 5K
Is September still too hot for a fast 5K in the South?
In the Southeast and Gulf states, September often feels more like summer than fall, especially early in the month. Humidity holds even when the thermometer dips, and that slows short efforts more than most runners expect. If you are racing in Atlanta, Houston, or anywhere along the Gulf, plan for an early start and do not chase a personal best without checking the forecast first.
What should I wear to a September 5K?
In the North and at elevation, a lightweight technical tee and shorts are usually enough, with a throwaway layer at the start if temperatures are cool. In the South, treat it like a summer race: minimal layers, moisture-wicking fabric, and sunscreen for morning events. The 3.1-mile distance moves fast, so you will warm up quickly regardless of where you start.
How far in advance should I start training to race a September 5K?
A focused six-to-eight-week sharpening block is enough if you have been running consistently through summer. If you are starting from scratch or coming back from a break, give yourself a full summer of base work first. September 5Ks reward runners who have been on their feet all summer, even if those weeks were slow and easy.
Is a September 5K worth traveling for?
It can be, but factor in the regional weather gap before booking. A race in a northern city or at altitude is likely to offer comfortable conditions, while a race in Florida or Texas may still be fighting summer heat. Finish times across September editions span a wide range, reflecting the full spread of climates and field types the month produces.
When in September are most 5K races held?
The busiest weekend is September 18 and September 19, with 92 of them, 65 of those on Saturday, September 18. Another 25 fall on a weekday, which is worth knowing if you are traveling for one.
What is a good 5K time?
Across the 191 of these September 5K races with published results from past editions, the median finisher ran 36:37, and the median winning time was 19:21. So anything under 36:37 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.
How big is a typical September 5K field?
The median one finished 100 runners, across the 191 of these September 5K races 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 1:07:02.
Which states have the most September 5K races?
Texas has 31, Florida has 24, Georgia has 13, Illinois has 12, Michigan has 12. If you are willing to travel, those are the states where a September weekend gives you the most to choose from.
Are there trail 5K races in September?
Yes, 23 races around the United States get you off the pavement: 12 are trail races, and 11 mix road and trail.