By our 5-axis Green Score, the CNO Financial Indianapolis Monumental is the easier race — 8.8/10 vs 7.4/10 for the TCS London Marathon (a 1.4-point gap). The biggest difference is entry, where the CNO Financial Indianapolis Monumental has the edge. Scores come from elevation profiles, 10 years of race-morning weather, entry odds, and field size — the full method is on the methodology page.
| Score (10 = easiest) | CNO Financial Indianapolis Monumental | TCS London Marathon |
|---|---|---|
| Green Score (overall) | 8.8 | 7.4 |
| First-timer score | 9.4 | 8.9 |
| Terrain | 8.8 | 9.2 |
| Climate | 10.0 | 10.0 |
| Entry | 10.0 | 2.6 |
| Travel | 5.0 | 2.0 |
| Field & support | 9.5 | 10.0 |
| Distance | marathon | marathon |
| Date | November 7, 2026 | April 25, 2027 |
| Location | Indianapolis, IN | London |
| Typical race-day weather (10-yr) | 44°F / dew 38°F | 48°F / dew 40°F |
| Elevation gain | 377 ft | 246 ft |
| Field size | 20,000 | 50,000 |
| Entry | open | lottery |
| Entry fee | $140 | $175 |
| Boston qualifier course | Yes | Yes |
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