Illinois is a fantastic state to chase a half marathon, especially in the late summer and early fall. The flat to gently rolling terrain, scenic trails, and vibrant communities make for memorable race experiences. Whether you're after a fast PR or a fun themed run, the Prairie State has something for you. Here are three upcoming half marathons worth adding to your calendar.
Naperville Trails Half Marathon & 10K — September 5, 2026 (Wheaton)
With a Runner Favorite quality score of 81, this race is a standout. It winds through the scenic DuPage River Trail system, offering a mix of paved paths and wooden bridges. The September date means cooler temps, and the course is known for being runner-friendly. It’s a great option for first-timers and veterans alike.
Hidden Gem Half Marathon — September 12, 2026 (Flossmoor)
True to its name, this race in Flossmoor scored an 80 and is a local favorite. The course takes you through quiet neighborhoods and wooded areas, with a community vibe that’s hard to beat. It’s held the weekend after Naperville, so you could even do both for a back-to-back challenge.
Christmas in July Half Marathon and 5K (Chicago area) — July 18, 2026 (Elk Grove Village)
If you love holiday spirit in the middle of summer, this is your race. The theme includes festive decorations, holiday music, and even a chance to meet Santa. It’s a fun, no-pressure event perfect for runners who want to mix up their training with something lighthearted. The quality score of 64 reflects its more casual nature, but the energy is top-notch.
For the full list of upcoming half marathons in Illinois, including more details on these races and others, visit our Illinois half marathon directory. Whether your goal is a PR or just a great experience, you’ll find the right race to keep your adventure going.