Compare marathon courses
Two races, one table. Climbing, net drop, the BQ downhill adjustment, and five years of observed race-morning weather — the numbers that actually separate courses.
The read
- Chicago Marathon climbs 476 ft less than California International Marathon (CIM). Total climbing is the course factor physiology says costs you the most, so this is the single biggest difference between the two courses.
| California International Marathon (CIM) | Chicago Marathon | |
|---|---|---|
| Next edition | Dec 6, 2026 | Oct 11, 2026 |
| Location | Sacramento, California | Chicago, Illinois |
| Course character | Net downhill · point-to-point | Flat · fast · loop |
| Total climbing | 663 ft | 187 ft |
| Net elevation change | 366 ft downest. | 10 ft upest. |
| Steepest grade | — | — |
| BQ adjustment | None | None |
| Course speed | Fast | Very fast |
| Avg race-morning temp | 46°F (5-yr avg) | Not compiled yet |
| Avg dew point | 44°F (5-yr avg) | Not compiled yet |
| Warmest observed morning | 53°F in 2023 | Not compiled yet |
| USATF certification | CA18004DT | — |
Where the numbers come from
Climbing and net drop come from each course's elevation data. Figures marked est. are our estimates rather than official race data — fine for describing a course, not for splitting hairs between two close ones.
Race-morning weather is five years of observed conditions (7–11am at the start line), not climate averages: Open-Meteo historical reanalysis (ERA5), 7-11am local at the start line. Where a race shows no weather row, we have not compiled its history yet.
The BQ adjustment is the B.A.A.'s net-downhill rule for the 2027 Boston Marathon: +5:00 for 1,500–2,999 ft of net drop, +10:00 for 3,000–5,999 ft, and courses at 6,000 ft or more cannot be used to qualify.