The Boston Athletic Association on Friday announced weather-related changes to Monday’s Boston Marathon schedule to ensure the safety of participants, pushing the Wave 4 start time immediately behind Wave 3 (10:50 a.m.).
Because the forecast calls for cool morning temperatures and windy and rainy conditions, the BAA eliminated the 25-minute gap between Waves 3 and 4 to reduce the amount of time runners will have to wait at the athletes’ village in Hopkinton.
Preparations have been made to ensure the safety of everyone along the route, including accommodations for overflow at medical aid stations, ponchos and hand warmers for volunteers, adjustments to staging areas that include tent walls and heaters, and enhanced gear-check stations.
The Boston Marathon has never been canceled or postponed in its 122-year history, although it was stopped in 2013 after two bombs were detonated near the finish.
Last year’s marathon also was run in cold, rainy conditions.
“The thing about last year is that the conditions weren’t dangerous like 2012 with the heat,” race director Dave McGillivray said. “They were just uncomfortable and miserable. That’s why we weren’t considering cancellation, as we’re not considering it this year.
“The most important message we can get out to all the runners is to take personal responsibility for themselves. I kiddingly always say that we can’t fit 30,000 of you in our medical tent. You have to make sure that you’ve dressed accordingly and that these are conditions that you can participate in safely. So it’s your decision whether to run or not.”
The National Weather Service said a period of showers with embedded heavy rain and possibly thunderstorms will develop Sunday night and continue into Monday afternoon.
Around start time, the temperature is expected to be in the upper 40s to 50. Highs Monday afternoon are expected to reach the mid 60s. There is a chance of thunderstorms between 5 a.m. and 3 p.m., according to weather service meteorologist Alan Dunham.
“It’s about an equal chance,” he said. “It’s not real confident we’re going to get them, but the potential is there for a possible one or two.”
“The problem with it getting warmer is the threat of thunderstorms,” McGillivray said. “Now, that’s something that we have to think about. Everything is a function of when and where because we’re 26 miles long, so something can be happening in Hopkinton and not in Boston or vice-versa.”
The BAA has contingency plans to make sure runners, spectators, and volunteers are prepared to deal with the conditions.
“We have operations along the course to communicate with runners and spectators to seek shelter,” said BAA communications manager Meg Reilly. “It depends a lot on the situation. There’s been a number of years where runners have been compelled to remove themselves from the race due to weather.
“We made our decision today as early as we could so our athletes can feel comfortable. Our approach is to have contingency plans for things we can manage and we already feel we’re in a good spot.”
Eligible athletes whose means of participation are directly affected by the conditions, such as wheelchairs or prosthetics, can elect to defer their participation and will be given complimentary entry into the 2020 Boston Marathon, with qualifying standards waived.Martin Finucane of the Globe staff contributed to this report. Dan Shulman can be reached at email@example.com. John Powers can be reached at firstname.lastname@example.org.