Heavy Rain Sleet and Snow to Slam the Boston Marathon Course Monday Between 1 PM and 7 PM
BOSTON, MASSACHUSETTS — A significant and disruptive weather system is threatening to deliver a curveball to the Boston Marathon on Monday April 20, with forecast data showing a band of heavy rain, sleet, and snow moving through the race corridor between 1:00 PM and 7:00 PM — directly overlapping with the peak hours of one of the world’s most iconic road races.
Mixed Precipitation Band Targets the Marathon Corridor Monday Afternoon
Precipitation type forecast data valid at 10:00 PM Monday April 20 shows a well-organized band of moisture pushing through southern New England, with rain dominating coastal areas while sleet and snow push inland across central and western Massachusetts, Connecticut, and Rhode Island. The mixed precipitation zone cuts directly through the Boston Marathon route and surrounding region.
Composite reflectivity data valid at 9:00 PM Monday shows a coherent and organized precipitation shield covering the entire greater Boston metro area, with moderate to heavy rain returns concentrated across eastern Massachusetts, Cape Cod, and Long Island Sound, and snow and sleet signatures visible across interior New England.
Liquid Equivalent Totals of 0.75 to Over 1.75 Inches Forecast
Six-hour QPF data valid through 10:00 PM Monday shows liquid equivalent precipitation totals of 0.75 to over 1.75 inches across a broad swath of southern New England, with the heaviest totals concentrated across eastern Massachusetts, Rhode Island, and Connecticut. The combination of rain, sleet, and snow across this liquid equivalent range signals a significant and impactful precipitation event for marathon participants and spectators alike.
| Region | Precipitation Type | Liquid Equivalent |
|---|---|---|
| Greater Boston and coast | Heavy rain | 1.25 to 1.75+ inches |
| Central Massachusetts | Rain mixing with sleet | 0.75 to 1.25 inches |
| Interior New England | Sleet and snow | 0.25 to 0.75 inches |
| Vermont and upstate NY | Snow | Variable |
Marathon Runners and Spectators Face a Brutal Afternoon
The 1:00 PM to 7:00 PM window covers the bulk of finish-line activity for the Boston Marathon, meaning tens of thousands of runners and spectators will be exposed to cold, wet, and potentially wintry conditions at the most critical point of race day. Hypothermia risk increases significantly for runners who slow or stop in cold rain and sleet conditions.
Anyone attending or participating in Monday’s marathon should prepare for full rain gear, extra layers, and rapidly changing conditions throughout the afternoon.
Stay with CabarrusWeekly.com for live Boston Marathon weather updates through Monday afternoon.
