Cloudy, Cool Day for BAA 5K

Cooler air settles into Boston area before rain arrives Sunday

Apr. 18, 2026 at 9:41am

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A sweeping, atmospheric landscape painting in muted tones of grey, blue, and green, with a group of small runners visible in the foreground against a backdrop of heavy, swirling clouds and mist.The dramatic, atmospheric conditions of the Boston Marathon weekend set the stage for an epic running event, where the power of nature dwarfs the human form.Boston Today

Cooler temperatures and cloudy skies are expected for the Boston Athletic Association 5K race on Saturday, with highs only reaching the upper 40s. While the race day will be dry, rain is forecast to move in on Sunday, with the potential for heavy downpours and even some wet snow in higher elevations. Temperatures will remain below average for the entire marathon weekend.

Why it matters

The weather conditions can have a significant impact on the performance and experience of runners and spectators at major running events like the BAA 5K and Boston Marathon. Cooler temperatures and cloudy skies can be ideal for runners, but may be less comfortable for spectators. The potential for heavy rain on Sunday could also disrupt the marathon festivities.

The details

Saturday's BAA 5K will see temperatures struggle to reach the 50-degree mark, with a chill in the air due to cooler air settling into the region. Clouds will be thick throughout the day, with the potential for some morning fog that should dissipate by late morning. The dry conditions will hold for the race, but rain is expected to move in on Sunday, with the heaviest rainfall focused north and west of Boston. There is also a chance of some wet snow mixing in at higher elevations. The rain is forecast to continue through Sunday evening before tapering off.

  • The BAA 5K race takes place on Saturday, April 18, 2026.
  • Rain is expected to move into the region on Sunday, April 19, 2026, and continue throughout the day.
  • The Boston Marathon is scheduled for Monday, April 20, 2026.

The players

Boston Athletic Association

The organization that hosts the annual Boston Marathon and related running events.

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What’s next

Runners and spectators should monitor the weather forecast closely in the days leading up to the marathon weekend and prepare accordingly. The potential for heavy rain on Sunday could impact event logistics and plans.

The takeaway

The cooler temperatures and cloudy skies on race day may provide ideal conditions for runners, but spectators should dress warmly. The rain expected on Sunday could disrupt the marathon festivities, so organizers and attendees will need to be prepared to adjust their plans as needed.