Runners taking part will love the temperatures and overall conditions — the race will start in the upper 30s to low 40s in Hopkinton and slowly tick up to the upper 40s, or just at about 50 degrees along the route to Boston.
The winds as of now could be pushing 10 to 20 mph across the region, which will make the wind chills feel downright brisk, especially at the start for runners and all day long for spectators along the route. Spectators will definitely want to wear layers.
Here’s your race course forecast during peak action throughout Monday.
A look at the weather forecast across the marathon route during peak action on Monday.Boston Globe
Below are the forecast wind chills around 11 a.m., Monday, for the region. This may make it feel somewhere in the mid-30s in the morning, and the low 40s in the afternoon.
Wind chills will likely sink to the mid-30s across Greater Boston the morning of Marathon Monday.Boston Globe
The strong high pressure should shift wind speeds to a northwesterly or westerly flow. This could set up a beneficial tailwind for runners. The winds may not be as strong or as perfectly positioned as the ideal southwesterly tailwind during the 2011 race, when Geoffrey Mutai of Kenya set a course record of 2 hours, 3 minutes, 2 seconds, but any kind of tailwind can certainly help.
Wind speeds will be at least 10 mph during the marathon, with some gusts pushing 15 to 20 mphBoston Globe
Timing of any precipitation. Don’t forget the sunscreen
Sunday’s frontal boundary won’t sink dramatically south of Eastern Mass., so there is a slight chance for a spot sprinkle to pop up during the day, but I’m holding those chances to less than 10 percent as high pressure should win the atmospheric position battle. Given how progressive our spring weather pattern has been, I do think that Sunday’s front will likely clear the region before the wheelchair race begins Monday morning, but there could be a trailing sprinkle before the high pressure takes over. If it does sprinkle, it would likely pop up during the afternoon.
Otherwise, we should see the sun come out in chunks as the day goes on, so it might be a good idea to wear sunscreen with the high sun angle, despite the chilly temperatures.
Take a look at the different forecast models below showing Monday morning as dry across Eastern Mass.
A front will clear the region on Marathon Monday, and a sliver of energy to the southwest may produce an isolated sprinkle late.Boston Globe
More on Marathon temperatures: Cooler air in the 40s
More cool air from Canada is set to settle in pretty quickly behind Sunday night’s front, wicking away moisture from Greater Boston by early Monday. This should set up decreasing clouds throughout the day with chilly air and perhaps a bit of a wind chill.
What does the cooler air actually mean? Well, temperatures will drop noticeably below the seasonal norm. So instead of the mild spring warmth we enjoyed this week, we’re looking at temperatures about 10 to 15 degrees below average for the Boston area.
Temperatures during the marathon, before the start, and during the afternoon.Boston Globe
Again, indications suggest race-morning temperatures starting in the upper 30s or low 40s, with afternoon highs only climbing into the mid- to upper 40s. Perhaps 50 degrees is possible during the afternoon.
Last year, morning temperatures edged into the mid-50s after scattered showers passed the night before. Hours later, the day hit a high of 73 under a clear, sunny day.
Marathon weather stats over the past two decades
• The average daily high over the past 10 marathons has been 61 degrees. The years 2017, 2020, 2021, and last year all soared above 70. Last year saw a high of 73, very warm for runners.
• The coldest marathon day since 2000 was in 2018, with the high reaching only 43 degrees. This time around might end up closer to the coldest marathon than the warmest.
• Four of the last 10 marathons saw rain, with 2023 the last year the course ran in wet conditions.
We will be closely monitoring the weather conditions all week, leading up to Marathon Monday, April 20. Keep up-to-date with the latest Globe forecast by signing up for our free daily Globe Weather Forecast that will arrive straight into your inbox bright and early each weekday morning.
Ken Mahan can be reached at [email protected]. Follow him on Instagram @kenmahantheweatherman.
