Boston Marathon numbers and forecast

The 130th Boston Marathon is set for Monday, April 20, with 30,000 runners expected on a cooler race day after a stretch of warmer weather. (wbur.org) (wmur.com) The Boston Athletic Association says 32,494 participants are entered and 30,000 are expected to start in Hopkinton, including runners from 137 countries and all 50 states. (baa.org) The race is scheduled for Patriots’ Day, Monday, April 20, 2026, and the course runs 26.2 miles from Hopkinton through Ashland, Framingham, Natick, Wellesley, Newton, Brookline and into Boston near Copley Square. (baa.org) (boston.com) This year’s field again mixes professional contenders with a much larger mass field, and the Boston Athletic Association says more than 10,000 volunteers support the event from start to finish. (baa.org) (boston.com) The weather outlook has shifted away from this week’s 70-degree warmth. WMUR reported on April 15 that “much cooler temperatures” are likely by Marathon Monday after several days of showers and possible thunderstorms beforehand. (wmur.com) National Weather Service forecast pages for Boston have also pointed to a cooler Monday than the midweek pattern, with highs in the upper 60s and a chance of showers in the latest outlooks posted this week. (weather.gov 1) (weather.gov 2) Boston’s race is the world’s oldest annual marathon, and organizers say it remains one of the Abbott World Marathon Majors, which helps explain why the field still draws runners from more than 130 countries. (boston.com) (baa.org) The scale reaches beyond the runners. The Boston Athletic Association says 1,800 medical volunteers are part of the volunteer corps, and the charity program is trying to top last year’s record $50.4 million raised. (baa.org) The final forecast will tighten over the next several days, but the early picture for April 20 is a packed starting line in Hopkinton and a cooler run into Boston than runners are seeing this week. (wmur.com) (baa.org)