Highs in the 40s look likely. It's possible that Monday's high temperature could set a record as a the coldest high in Boston Marathon history. The current record is 48 degrees for the 2009 marathon. Any overnight showers will taper off before sunrise and before any of the start times. Runners can expect partly cloudy skies with a cool breeze.

Tuesday, April 21 opened on the chilly side in Boston, with mostly clear skies and temperatures in the mid-30s (about 34°F at Boston Logan, KBOS). The sun looks like it will hang around through the afternoon,

Cloudy skies and possible rain await those in Boston as runners prepare for the Boston Marathon. Temperatures are expected to be in the upper 40s or low 50s for most of the day Monday with lows around 34 degrees,

Boston Marathon runners are in for favorably cool and breezy conditions through the race Monday, with a possibility of some afternoon showers hitting the city later and potentially some snow farther out in Massachusetts,

From heat risk to wet, rainy tracks, weather plays a significant factor in distance running. It's even more important to consider for the Boston Marathon, which is this Monday, April 20, 2026, as some pretty crazy marathon mishaps have happened as a result of New England weather.

What type of weather might runners expect for the 130th Boston Marathon on April 20? Here's an early look at the forecast.

As Boston Marathons go, the average temperature is in the lower 60s. This year we’re still going to remain mainly dry, but on the cooler side — nice for the runners but a bit chilly if you're a spectator.

Many marathon spectators had to pull out their winter coats as morning temperatures hovered in the 30s before the day warmed to the low 50s.

The mercury at the start of the race in Hopkinton should be in the upper 20s to mid 30s. It's possible Monday's high temperature could set a new record for temps recording in Boston for the marathon. In 2009, temps reached just 48 degrees.

Boston held its 130th Marathon on a chilly day that was the crowd endured and the athletes relished. By Victor Mather Braving chillier and windier conditions than usual, hundreds of thousands of Bostonians turned up to cheer at the 130th running of their hometown marathon on Monday.