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2021 Boston Marathon Weather Preview

Race, Weather

Race Forecast

October 11, 2021 - Boston, MA, USA

Overview

With the Boston Marathon being held in the Fall for the first time in its 125 year history, the weather is just about as unpredictable as your New England day. The race will be held on October 11th as the second major marathon of the Chicago -> Boston double header. The rolling start for all runners will start right at 9AM and continue until every runner has crossed the line. Unlike previous years where runners are traditionally released in waves, due to COVID-19 precautions there will be no congregation at the start line. Runners will be dropped off by the buses, take about 15 minutes to warm up, and start their race from Hopkington to Boston. All COVID-19 protocols can be seen on the official BAA website

Race Forecast

The forecast is difficult to compare this year because the Boston Marathon has never been run as a Fall race. While temperatures vary wildly in the New England spring, the Fall presents a crisp, but wavering decline in temperatures between September and November. The current forecast for race day are average, hovering around the mid-60s, and the dew point is a bit higher than what you'd want for your best performance. A partly cloudly outlook should prevent overheating in the sun and chance of rain is low. Expect an easy start without shivering but don't rely on running a PR if you've run Boston in the past with ideal conditions.

Boston Marathon Historical Weather

YearRunScoreTempHeat IndexHumidityDew PointRainWind (mph)Cloud CoverUV IndexWBGT
2019
9
60º60º87%56.12º05 17757%562º
2018
5
41º38º93%38.99º0.05514 69100%450º
2017
8
71º71º39%44.92º05 26827%665º
2016
8
70º70º27%34.34º03 644%662º
2015
8
44º42º85%40.33º05 10399%451º
2014
9
57º57º32%27.2º03 20911%655º
2013
8
51º51º49%32.49º01 14559%553º
2012
7
80º81º49%59.17º03 1870%675º
2011
9
51º51º37%25.32º04 28315%653º
2010
9
51º51º49%32.73º06 34326%653º
2009
9
49º48º48%30.3º04 11715%653º
2008
8
54º54º64%42.56º02 8325%655º
2007
6
48º46º92%46.06º0.04295 129100%452º
2006
9
50º50º55%34.77º02 1983%453º
2005
9
66º66º25%29.07º03 3535%659º
2004
8
71º71º48%50.59º07 2209%666º
2003
9
59º59º39%33.7º06 1192%755º
2002
9
52º52º96%50.54º0.0026 342100%455º
2001
8
48º44º41%25.38º08 7010%652º
2000
7
45º39º48%26.85º013 7955%550º
Historical data collected at the halfway point of the Boston Marathon course at 11AM ET. (42.2995851,-71.313448).
Source historical weather data Powered by Dark Sky. RunScore and WBGT estimates provided by Evening Run.
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