LOCATION · United States
Boston Weather Radar & Live Nor'easter & Snow Map
Is this nor'easter going to bury Boston in snow or just rain it out?
Boston's weather has a personality, and most of it is written in winter. While the city sees its share of summer heat and the occasional brush with a tropical system, what truly defines New England's largest city is the cold season: the nor'easters that come howling up the coast, the blizzards that shut the city down, the Arctic outbreaks that follow a wandering polar vortex, and the coastal floods that arrive when a storm lines up with a high tide. Reading those threats apart is the heart of a Boston winter, and it's exactly what the live map is for.
The nor'easter: New England's signature storm
The nor'easter is the storm that defines the region. These systems develop along the East Coast and intensify as they move northeast, drawing cold air down from Canada and a deep supply of moisture in off the Atlantic. Boston sits in the worst of it — on the side of the storm where the heaviest snow, the strongest winds and the biggest waves come together.
A strong nor'easter can drop one to two feet of snow, drive blizzard conditions with whiteout winds, and pile the ocean against the shore all at once. The city's most memorable winters are measured by them. Because the storms strengthen as they pass, the worst conditions often arrive late, after the first flakes have already lulled everyone into thinking they know how it will go.
The rain–snow line: a few degrees decide everything
The hardest part of forecasting a Boston storm isn't whether it will hit — it's what falls when it does. A nor'easter pulls in two competing air masses: cold air from inland and the north, and milder air off the ocean to the east. The boundary between them, the rain–snow line, frequently cuts straight across Greater Boston.
The result is a city that can experience three different storms at once. Inland and northern suburbs pile up heavy snow. Coastal neighbourhoods, nudged warmer by the nearby ocean, may flip to rain or a slushy, ice-laden mix. And the zone in between gets the worst of both. A shift of just a few degrees, or a few miles in the storm's track, decides who shovels powder and who gets soaked.
When the polar vortex comes calling
Separate from the storms is the cold itself. When the polar vortex — the band of frigid air that normally stays bottled up over the Arctic — weakens and breaks down, lobes of that air spill south, and New England is a frequent target. Boston can drop into dangerous, bone-deep cold, with wind chills plunging well below zero.
These outbreaks are their own kind of hazard. They can arrive on a clear, snowless day, so the threat isn't a storm to track but the raw cold to endure — frostbite, frozen pipes, strain on the heating grid. New Englanders watch for them as closely as they watch for snow.
The coastal flooding twist
Boston's geography adds one more wrinkle. When a nor'easter's onshore winds coincide with a high tide — especially an astronomically high one — the sea piles up against the coast and floods low-lying neighbourhoods and harbour-front streets. It's the same storm-surge physics that threatens hurricane coasts, just delivered by a winter storm. The timing of the tide can be the difference between a wet street and a serious flood.
Reading it on the live map
A Boston winter storm is best read with three layers at once:
- Watch it arrive. Turn on Radar to see the precipitation move in and track where it's heaviest.
- Find the rain–snow line. Add Temperature to see where it's cold enough for snow and where the coast is flipping to rain — the single most useful thing to know here.
- See the whole storm. Use Satellite to watch the system's structure spin up the coast and gauge how organised and powerful it's becoming.
- Mind the cold and the tide. During an Arctic outbreak, temperature is the whole story; during an onshore-wind storm at high tide, think about coastal flooding, as the storm-surge guide explains.
Radar tells you when it hits, temperature tells you what falls, and satellite tells you how bad it gets. In a city where a single storm can be powder, rain and flood all at once, reading the three together is how you know which Boston winter you're about to get.
Frequently asked questions
What is a nor'easter, and why does Boston get so many?
A nor'easter is a powerful storm that develops along the U.S. East Coast, named for the strong northeasterly winds that batter the coast as it spins up. Boston sits right in their firing line: storms riding up the coast pull cold air down from the north and moisture in off the Atlantic, and the city is perfectly placed to catch the heaviest snow, fierce winds and pounding surf on the storm's western and northern side. They're the defining winter event of New England.
Why does the same storm dump snow in one suburb and rain in another?
It comes down to a few degrees of temperature. A nor'easter pulls in both cold air from inland and milder ocean air from the east, and the dividing line between them often slices right across Greater Boston. Towns just inland and to the north stay cold enough for heavy snow, while spots near the coast can warm just enough to flip to rain or sleet. That razor-thin rain–snow line is why Boston forecasts hinge on a degree or two.
How does the polar vortex affect Boston?
When the polar vortex weakens and Arctic air spills south, Boston can plunge into dangerous, bitter cold — sometimes with biting wind that drives the feels-like temperature far below zero. These cold snaps can arrive with or without snow, and they're a separate hazard from the storms themselves: the threat is the raw cold, not the precipitation. Watching for these outbreaks is a New England winter ritual.
How do I track a winter storm on the map?
Turn on Radar to watch the precipitation arrive and see where it's falling, and the Temperature layer to find that crucial rain–snow line. Add Satellite to see the whole storm's structure spinning up the coast. Together they show you not just when the storm hits, but whether your part of the region ends up under snow, rain or the messy mix in between.
SEE IT LIVE
Everything in this guide is on one real-time map.