This past year was another of the hottest years on record in New Hampshire, as the warming trends of climate change continue -- faster in this region than many others, especially in winter.
From January to November of 2020, New Hampshire saw its fourth-hottest average temperatures since the late 1800s, according to state climatologist and UNH associate professor Mary Stampone.
January to November of 2020 was about 4 degrees Fahrenheit warmer than the historic average, Stampone said. That’s also about how much the state has warmed overall since the late 1800s.
She said 2020 had New Hampshire's second-warmest summer, and seventh-warmest winter, for the season that began in 2019. Winter is the state’s fastest-warming season.
“When you do all the top-tens, it’s the past twenty years that just stack up at the very top for the warmest years,” Stampone said.
Humans’ use of fossil fuels is warming the planet in line with scientific projections, Stampone said, and those trends don’t show signs of slowing down.
“This is along the lines of that worst-case-scenario, business-as-usual curve, because we’re not really large-scale mitigating climate change, at least right now,” she said. “Hopefully that will change.”
If not, research suggests New Hampshire will become more like the mid-Atlantic within decades – with milder, rainier winters and hotter summers.
From May 2020 to just weeks ago, those changes helped drive one of the worst droughts New Hampshire and New England have seen in decades, even as the area sees heavier bouts of precipitation overall.
The drought caused major crop losses, drinking water shortages and small forest fires. And Stampone said well users should remain conservative in the coming months -- because the drought's effects on groundwater could linger into spring 2021 if this winter turns out to be mild.
“If we get less snowfall, there’s less snowpack to kind of melt and refresh everything in the spring,” she said.
2020 also saw many instances where conditions in New Hampshire were hotter or rainier on particular dates than in any other year on record. Stampone said these kinds of extremes and anomalies are also growing more frequent as the climate warms.
This story is part of By Degrees, NHPR's climate change reporting initiative. Click here to learn more.