When in May are most 5K races held?
The busiest weekend in Illinois is May 29 and May 30, with 9 of them, 7 of those on Saturday, May 29. One more falls on a weekday, which is worth knowing if you are traveling for it.
Race calendar · May 2027 · Illinois
5K Races in Illinois in May 2027
Every 5K in Illinois in May 2027, all 31 of them, sorted by date. Dates, entry fees, finish-time stats from past results, and start-line maps.
What the field actually runs
May 5K Races, By the Numbers
35:32Median finish time
18:38Median winning time
66Median field size
13May 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 May
The May Race Weekends
5K races are not spread evenly across May. 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 May 5K races that stand out on the numbers: the biggest field, and the longest unbroken run of editions.
Illinois 5K Races by City in May
All 5K Runs in Illinois in May
31 total Sat, May 1, 2027Kirby Derby Monticello, ILRegistration opens Jan 1, 2027From $25Details Sat, May 1, 2027Byron Rocks 5k & 10k - Run it. Walk it. Ruck it. Byron, ILFrom $40Details Sat, May 1, 2027Northern Illinois Food Bank's Fight Hunger 5K I 10K I 1-Mile Wheaton, ILFrom $35Details Sat, May 1, 2027Miles for Smiles 5K McHenry, ILRegistration opens Dec 1From $15Details Sat, May 1, 20273rd Annual Red Wolves on the Run 5K Lansing, ILRegistration closedPricing TBADetails Sun, May 2, 2027Unit 5K Normal, ILRegistration opens Dec 1From $10Details Sun, May 2, 2027Tailwagger Trot Lisle, ILRegistration opens Jan 31, 2027From $35Details Sat, May 8, 2027Starved Rock Country Marathon Ottawa, ILFrom $45Details Sat, May 8, 2027Hometown Half Marathon/5K/10K - Greater Chicago Elk Grove Village,, ILFrom $38Details Sat, May 8, 2027Pink 5k Oak Brook Park District Oak Brook, ILRegistration opens Jan 1, 2027From $25Details Sat, May 8, 2027Quarryman Challenge Lemont, ILRegistration closedFrom $40Details Sat, May 8, 2027Lace Up for a Cause: For A Better Tomorrow 5K & 2K Bloomington, ILRegistration opens Feb 1, 2027From $15Details Sat, May 8, 2027Run for Chocolate 5k/10k/13.1 CHICAGO/EVANSTON Chicago, ILFrom $30Register Sun, May 9, 2027Barrington Mother's Day 5K Run/Walk Barrington, ILFrom $45Details Sat, May 15, 2027Run for D103 5K Run/Walk Lincolnshire, ILRegistration opens Nov 18From $25Details Sun, May 16, 2027I Got Your Six Walk/Run Bourbonnais, ILRegistration opens Feb 4, 2027From $35Details Sun, May 16, 2027Dash for the Dogs 14th Annual 5K Run/Walk Barrington, ILFrom $35Details Sat, May 22, 2027Frontline OCR Byron, ILFrom $79Details Sat, May 22, 2027Lap the Lake 5K & Fun Run Ina, ILRegistration opens Feb 1, 2027From $25Details Sun, May 23, 2027Kenilworth Memorial Day 3.5k (2.2 Mile) Run / Walk Kenilworth, ILRegistration opens Apr 13, 2027FreeDetails Sun, May 23, 2027Hitchhikers Spirits Run 5k/10k Joliet, ILFrom $30Details Sat, May 29, 2027Cogs Run 5K Genoa, ILRegistration opens Dec 1From $25Details Sat, May 29, 2027Onarga ALA Poppy 5K Onarga, ILRegistration opens Jan 1, 2027From $30Details Sat, May 29, 2027Goose Creek Classic Odin, ILRegistration opens Mar 16, 2027From $20Details Sat, May 29, 2027Neoga Days 5K & 1Mile Run/Walk Neoga, ILFrom $30Details Sat, May 29, 2027WARRIOR RUSH: Clash of Olympus 5K - 10K - Half Marathon 13.1 - Full Marathon 26.2 Wheaton, ILFrom $30Details Sat, May 29, 2027SuperHeroes Run CHICAGO/EVANSTON Chicago, ILFrom $30Register Sat, May 29, 2027SuperHeroes Run SAN ANTONIO San Antonio, ILFrom $30Register Sun, May 30, 2027Race To the Flag Westmont, ILFrom $20Details Sun, May 30, 2027The Memorial 5K Lake Barrington, ILFrom $25Details Mon, May 31, 2027Nina LeCuyer Memorial 5K Sheridan, ILFrom $35Details
Common Questions About Running a May 5K in Illinois
What is a good 5K time?
Across the 13 of these May 5K races with published results from past editions, the median finisher ran 35:32, and the median winning time was 18:38. So anything under 35:32 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 May 5K field?
The median one finished 66 runners, across the 13 of these May 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 1:00:04.