Patriots’ Day and Boston Marathon Weather Forecast

Boston, Massachusetts | Third Monday in April
By Caleb Weatherbee, Farmers’ Almanac

Each spring, New England welcomes one of its most celebrated traditions: Patriots’ Day and the Boston Marathon. As runners take to the historic course from Hopkinton to Boston and spectators line the streets, all eyes turn not only to the race—but to the skies above.

Patriots’ Day and Boston Marathon Forecast

First: About The Forecast

The Farmers’ Almanac’s long-range weather forecasts are based on our closely guarded “secret weather formula” dating back to 1818, known only to a small number of people within the publication and credited to their prognosticator persona, “Caleb Weatherbee” (more on him below). While the exact method is proprietary and not publicly reproducible, we can say that it relies on a blend of astronomical and atmospheric indicators, including sunspot and solar activity cycles, lunar influences such as tidal action, planetary positions, and other undisclosed factors, using these signals to project weather patterns months in advance.

Patriots’ Day and Boston Marathon Weather Outlook

Expect a generally mild and pleasant Patriots’ Day and Boston Marathon, with springlike temperatures and intervals of sunshine.

The day should begin on the cooler side, as is typical for April mornings in Massachusetts, but temperatures are expected to moderate as the day progresses. Skies will likely feature a mix of sun and passing clouds, with brighter breaks possible through late morning and afternoon.

Winds should remain fairly manageable, though occasional breezes may develop along exposed portions of the route. The overall risk of rain appears low, but New England’s changeable nature means a brief passing shower cannot be ruled out entirely.

Almanac Advice for Runners & Spectators

For runners, plan for a cool start by wearing throwaway layers and dressing as if it’s warmer than it feels, knowing conditions should turn comfortable as the race goes on; stay mindful of occasional breezes and be ready if the sun breaks out later in the day. Spectators should prepare for changing conditions by layering up for the chilly morning, bringing sun protection for brighter stretches, and packing a light poncho just in case of a brief shower—overall, it’s a favorable day to be outside, but flexibility will be key to staying comfortable.

Sunscreen, water, and breathable clothing are strongly advised.

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Farmers’ Almanac Final Word

Patriots’ Day and the Boston Marathon are famous for unpredictable conditions, but this year is shaping up to be a relatively pleasant one. Expect springlike temperatures and intervals of sunshine, with a cooler start giving way to milder conditions as the day goes on. Skies should feature a mix of sun and passing clouds, with brighter breaks possible into late morning and afternoon. While a few breezes may develop along exposed sections of the course, winds look manageable overall. Rain chances appear low, though—true to New England form—a brief passing shower can’t be ruled out.

— Caleb Weatherbee
Farmers’ Almanac

AboutCaleb Weatherbee

Caleb Weatherbee is the pseudonym used by the Farmers’ Almanac to represent the team of forecasters responsible for its annual long-range weather predictions. Introduced in 1983, the name protects the identity of those behind the forecast and preserves the secrecy of the Almanac’s methods.

The Farmers’ Almanac dates back to 1818, when its first editor, David Young, created a forecasting formula based on astronomy and mathematics. That system guided predictions for decades and continued after Young’s death in 1852, later overseen by editor Samuel Wright. By 1870, the Almanac had published its 52nd forecast, the same year the National Weather Service was founded.

Under the Weatherbee name, the Almanac continues to issue detailed seasonal outlooks. Former longtime editor Ray Geiger once estimated the Almanac’s accuracy at around 80%, a claim that has helped maintain its credibility for more than 200 years. Caleb Weatherbee remains a trusted symbol of the Almanac’s enduring forecasting tradition.