Fastest Marathons in May

This list ranks the fastest marathons in May based on the race's Personal Record (PR) Score. The PR Score for each marathon is created from an algorithm derived from research on how grade, elevation, and wet bulb temperature and ambient temperature affect marathon running performance. For more detailed information, please visit the FAQ.

The BQ % is the percentage of runners who qualified for the Boston Marathon according to the latest race results. Although it is not always indicative of a fast or slow course, the percent of Boston Marathon qualifiers can provide insight into the quality of the field and/or the speed of the course.

To see a ranking of marathons based only on the course (no weather impact), visit the Fastest Marathon Courses page.

The list only includes certified marathon courses. Keep in mind that PR Scores and ranking assume very good course management and pacing - especially for the extremely downhill races.