The past year has been marked by extreme weather across New England — punctuated by an extreme Arctic blast, followed by relentless rains that even now aren’t letting up.
Scientists say many of these events track with what’s expected with a warming — and already warmer — planet.
The mid-December storm, which inundated the East Coast under as much as 7 inches of rain and battered it with high winds, seems to be yet another bullet point in this relentlessly rainy year, which also has the distinction of being Earth’s hottest year in recorded history.
“One of the clearest symptoms of climate change is more heavy precipitation events like these,” said Jennifer Francis, senior scientist at the Woodwell Climate Research Center in Woods Hole. “There is no doubt that human-caused warming is a culprit in these extremes, but the strong El Niño raging now added even more fuel to the fire.”
As we prepare for a new year, here’s a look back at the year that was, told through the harshest weather events that tested even the heartiest New Englanders among us.
In the midst of a mild winter, an Arctic blast
January 2023 started off exceptionally mild, with Boston recording average temperatures more than 7 degrees higher than the historic record. But all that changed in early February.
Temperatures dropped to 10 degrees below zero on Feb. 4 at Logan International Airport. The small town of Hawley, in western Massachusetts, recorded what appeared to be the state’s coldest temperatures, reaching minus 22 degrees overnight.
At New Hampshire’s Mount Washington, home to some of the region’s most extreme weather, meteorologists at the observatory recorded wind chills of minus 108 degrees — likely the coldest wind chill ever recorded in US history.
Across the region, pipes froze, thousands lost power, and the thousands of residents who have shifted off fossil fuels for home heating saw their electric heat pumps tested in the most extreme way (a test that readers told us they largely passed with flying colors).
Francis Tarasiewicz, a weather observer and education specialist at the Mount Washington Observatory, told the Globe that climate change appeared to be behind the chilly blast, because warm air at the North Pole was causing the jet stream to be less stable and sag south, delivering “really true Siberian Arctic air” to the lower latitudes.
The winter that wasn’t
It may have felt like all of winter was condensed into that one blustery weekend in February. Because as quickly as it came, it was gone — leaving a less-than wintry winter behind.
With just over a foot of snow, the winter of 2022-2023 had the second-lowest snowfall on average in the Boston area, according to federal weather data. And it tied the winter of 2015-2016 for the warmest on record.
On Feb. 16, Boston reached 62 degrees, breaking a record high for that date, according to the National Weather Service. Maple sugaring season started a month early for some, and spring wildfires appeared in full bloom in February.
March Nor’easter
A powerful nor’easter swept across the Bay State in mid-March, bringing driving rain, heavy snow, damaging winds, and pounding surf.
Boston and Cape Cod received minimal snow, but Worcester and other cities in central Massachusetts accumulated as much as 3 feet. This nor’easter also left more than 32,000 Mass. residents without electricity.
El Niño emerges
Starting in March, climate scientists started noticing something alarming: the surface of oceans were far hotter than normal. That heat escalated in April and May, setting new records, before really taking off in June, with temperatures more than a full degree Fahrenheit higher than the historic mean from 1982 to 2011.
What was at play, it turned out, was the emergence of an El Niño weather pattern, a naturally occurring phenomenon that tends to bring warmer water to the surface of the ocean. That, in addition to the warmth from climate change that had been absorbed by the ocean, resulted in startlingly high temperatures at ocean surface, creating extra fuel for hurricanes and potentially influencing the migration of ocean species.
“I’m just so worried these days, I can’t even tell you,” Glen Gawarkiewicz, an ocean scientist at the Woods Hole Oceanographic Institution who studies coastal oceanography and changes to the Gulf Stream, said in June.
Wildfire smoke
As spring turned to summer, a new problem blew into New England: wildfire smoke. Across Canada, more than 400 wildfires were raging, sending large plumes of dense smoke toward the Northeast and eventually engulfing New England, New York, and Washington, D.C.
The smoke cast an orange haze that lingered heavy in the air for weeks, sending air quality alerts soaring. Health experts warned of the dangers posed by the elevated concentrations of fine particles in the smoke. Many people could even taste the smoke in the air as health officials advised the public to limit outdoor activities.
The wildfires and smoke began in May and lasted as late as October, rounding out a record-setting season of Canadian wildfires.
Vermont floods
Two months’ worth of rain fell in 48 hours in Vermont in July, inundating cities and towns, destroying roads and bridges, and leaving many residents homeless and without any possessions. Two people died in the flood waters as President Biden declared a federal emergency.
The National Weather Service said the flooding rivaled, if not exceeded, the damage witnessed when Hurricane Irene struck the region in 2011. The flood has since been dubbed the Great Vermont Flood of 2023.
“The devastation is far-reaching,” Governor Philip Scott said in July. “Although the coming days, weeks, and months will be incredibly difficult, we’ve faced challenges before, and Vermonters have risen to meet the moment.”
Heat wave tests schools
Across Massachusetts, schools reopened for the year amid an intense heat wave — with relentless temperatures well into the 90s in some places. As the temperature outside rose into the low 90s, classroom temperatures soared nearly as high.
Experts said that many schools across New England were not prepared for such extreme heat, largely because they were built at a time when they didn’t expect it.
Leominster floods
Torrential rain caused catastrophic flooding in this central Massachusetts city on Sept. 11, washing out roads and train tracks and leaving much of the downtown underwater.
“I just listened to the story of a woman who had never seen any flooding on her property, ever, and had 6 feet of water in just a couple of hours last night,” Governor Maura Healey said in September. “Devastating. Six feet. That’s our reality right now.”
New England’s December storm
A storm that killed two people in Massachusetts and two in Maine on Dec. 18 also triggered severe flooding in New Hampshire and Maine as well as widespread damage in Vermont. The deluge of windswept rain knocked out power to more than 58,000 customers in Massachusetts, and about 400,000 customers were without power in Maine as of Dec. 19 — less than two days after rain began.
In addition to the water damage caused by the rain and flooding, powerful winds caused even more destruction to homes and infrastructure. Several roads and highways were washed out or submerged as the Kennebec River and other waterways rose.
“Extreme precipitation events are becoming more common as the climate warms, particularly in relatively wet regions like the Northeast,” said Michael Rawlins, associate director of the Climate System Research Center at the University of Massachusetts Amherst. These “top 1 percent of events have increased about 60 percent in the Northeast, more than any other region in the US.”
Sabrina Shankman can be reached at sabrina.shankman@globe.com. Marianne Mizera can be reached at marianne.mizera@globe.com. Follow her @MareMizera. Vivi Smilgius can be reached at vivi.smilgius@globe.com. Follow her @viviraye.