The Boston Marathon has, yet again, been postponed because of the coronavirus pandemic.

The famed marathon will not be held on its traditional date of the third Monday in April, or Patriots’ Day, the Boston Athletic Association announced Wednesday. The 2021 Boston Marathon has been pushed from April until at least the fall.

No new date has been determined yet. Registration details and the field size have not been decided either.

“With fewer than six months until Patriots’ Day and with road races prohibited until Phase 4 of the Massachusetts reopening plan, we are unable to host the Boston Marathon this coming April,” said Tom Grilk, C.E.O. of the B.A.A. “By shifting our focus to a fall date, we can continue to work with stakeholders to adjust the in-person experience for runners and supporters alike. Prioritizing the safety of participants, volunteers, spectators, and community members, we continue to assess all elements of the race including a potential reduced field size or weekend date.”

The 2020 Boston Marathon was not held as originally scheduled on April 20. The race was first postponed and then canceled on May 28. Instead, the 124th Boston Marathon became a virtual event, taking place from Sept. 5-14. 

Nearly 18,000 people entered the marathon, which allowed participants to run 26.2 miles within a six-hour time period over 10 days.

“We are optimistic that the Boston Marathon will continue its tradition of celebrating the spirit of community and athletic excellence next fall. We know there will be many questions and we will look to address them in the coming months ahead,” Grilk said.

Boston Marathon A detail of the Boston Marathon finish line on April 20, 2020 in Boston, Massachusetts. Due to the coronavirus (COVID-19) pandemic, the race was rescheduled to September 14, 2020 instead of being run on April 20, Patriot's Day. Photo: Maddie Meyer/Getty Images