When in September are most 5K races held?
The busiest weekend in Illinois is September 25 and September 26, with 6 of them, 4 of those on Saturday, September 25. Every one of them is on a Saturday or a Sunday.
Race calendar · September 2027 · Illinois
5K Races in Illinois in September 2027
Every 5K in Illinois in September 2027, all 12 of them, sorted by date. Dates, entry fees, finish-time stats from past results, and start-line maps.
What the field actually runs
September 5K Races, By the Numbers
38:57Median finish time
19:33Median winning time
196Median field size
9September 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.
Illinois 5K Races by City in September
All 5K Runs in Illinois in September
12 total Sat, Sep 4, 2027Eckert's Spiked Apple 5k Belleville, ILFrom $25Details Sun, Sep 12, 2027Rock and Run for Mental Health 2027 Springfield, ILFrom $35Details Sat, Sep 18, 2027For Kids' Sake International Superhero 5K Carbondale, ILRegistration opens Jun 9, 2027From $25Details Sat, Sep 18, 2027Kennekuk Road Runners - Wild Wild Wilderness Oakwood, ILFrom $30Details Sat, Sep 18, 2027Nehemiah 5K Run/Walk Heyworth, ILRegistration opens May 3, 2027From $10Details Sat, Sep 18, 2027Golden Harvest Half Marathon & 5K/10K - Greater Chicago Greater Chicago, ILFrom $38Details Sat, Sep 25, 2027Stone Bridge Half Marathon and 5k Roscoe, ILRegistration opens Jan 27, 2027From $30Details Sat, Sep 25, 2027Lawndale 5K Chicago, ILFrom $20Details Sat, Sep 25, 2027Race to Cure Sarcoma Chicago Chicago, ILFrom $10Details Sat, Sep 25, 2027Centerstone's 5th Annual Life;Story 5K Run/Walk for Suicide Prevention Marion, ILFrom $35Details Sun, Sep 26, 2027DeKalb Corn Classic DeKalb, ILRegistration opens Mar 31, 2027From $30Details Sun, Sep 26, 20272027 D54 Education Foundation Run to Read Schaumburg, ILRegistration opens Jan 1, 2027From $5Details
Common Questions About Running a September 5K in Illinois
What is a good 5K time?
Across the 9 of these September 5K races with published results from past editions, the median finisher ran 38:57, and the median winning time was 19:33. So anything under 38:57 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 196 runners, across the 9 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 1:24:23.
Are there trail 5K races in Illinois in September?
Yes, one race around Illinois gets you off the pavement: 1 is a trail race.