Boston Marathon weather

Race-day forecast

April 19 in past years

At the start, 10 AM to 2 PM local time. “Heat” is the typical slowdown at the same effort, from temperature plus dew point. From Open-Meteo’s historical weather (ERA5).

About the course

A point-to-point course running east-northeast from Hopkinton to Boylston Street, net downhill, with the Newton hills between miles 16 and 21. Because it runs one way, wind direction matters more here than at almost any other marathon: a westerly is a tailwind the whole way, an easterly off the ocean is a cold headwind. Waves start through the morning; this page uses 10 AM to 2 PM. Official site: baa.org.

Your own runs, any day

Open a route in Route Forecast and choose Run for the weather along it at your pace, what to wear, and on warm days how much the heat will slow you. Open a route · Heat pace calculator · What to wear running

Questions

What’s the weather forecast for the Boston Marathon?

The race-day forecast for the course appears on this page from about 16 days before the race, with the temperature at the start and along the course, dew point, how much the heat is likely to slow you, wind and rain. Until then the page shows the weather on April 19 in each of the past ten years.

What is the weather usually like at the Boston Marathon?

See the table on this page: the temperature at the start, the high, dew point, wind and rain on April 19 for each of the last ten years, with the typical, coldest and warmest starts.

What should I wear for the Boston Marathon?

Dress for about 15–20°F warmer than the forecast once you’re racing, and bring throwaway layers for the wait at the start. From 16 days out this page lists what to wear for the forecast; the what-to-wear-running calculator covers any conditions.