Chicago is Sunday 10 October 2027. The start is Columbus and Monroe in Grant Park, and the finish is Columbus south of Balbo. The limit is 6 hours 30 minutes. Non-charity entry is $250 or $260 before the processing fee, and the general application date in this record has passed. There is no GPX, and we still do not have a surveyed pin for that start intersection.
The FAQ, opened 4 November 2026, says the 49th running is Sunday 10 October 2027. The start is Grant Park at Columbus Drive and Monroe Drive. The finish is Columbus Drive south of Balbo Drive. Time limit 6 hours 30 minutes. The participant page prints a Sunday schedule and says the times can change. No GPX. We do not have a surveyed pin for the Columbus and Monroe intersection.
The 2027 FAQ places the start in Grant Park at Columbus Drive and Monroe Drive and the finish on Columbus Drive south of Balbo Drive. The time limit is 6 hours 30 minutes. There are 20 aid stations. No GPX was on the FAQ. The Columbus and Monroe intersection did not geocode, so the stored start pin is the earlier Grant Park coordinate. The 57 m and 30 m figures stay historical.
Difficulty and PR scores
Difficulty is the course and the conditions. The PR score is a separate read on a fast clock. Missing inputs are dropped and the other weights are rescaled. The method, with the weights.
- Difficulty
- 29 / 100
Weight used: 70%. Need 40% before we print a number.
- PR / BQ friendliness
- 51 / 100
Band: mixed. Weight used: 60%. Need 45% before we print a number.
Weather median for 2011–2025, race date ±7 days, 225 days, at Earlier Grant Park pin (not a survey of Columbus and Monroe). Grid elevation 187 m.
BQ rate 16.1% on 2025 Chicago Marathon (8761 qualifiers). Source.
| Input | 0–100 | What went in |
|---|
| G Gain | — | No trusted gain per km. Uncertain stored gain is not used. |
| A Altitude | 0 | 187 m. 0 below 300 m, 100 at 2000 m. Source: open-meteo-grid. |
| H Heat | 50 | High 18.4°C, dew point 9.4°C. The hotter of the two bands is used. |
| W Wind | 40 | 4.56 m/s median. Bands: under 3 → 15, under 5 → 40, under 8 → 70, else 100. |
| C Cutoff | 25 | 390 min. A 5:00 marathon maps to 100 and a 7:00 marathon maps to 0, scaled by distance. |
| S Surface | 15 | road. Road 15, mixed 45, gravel 70, trail 90. |
| T Cool temps | 50 | 100 minus heat (50). |
| B BQ evidence | 53.7 | 16.1% on 2025 Chicago Marathon. 0% maps to 0 and 30% maps to 100. https://www.findmymarathon.com/bostonmarathonqualifiers-2027.php |
| E Execution | 50 | Cutoff 390 min on 42.2 km. Pacers and a course certificate are not in this record, so they add nothing. |
