On Sept. 30, a team composed of geography professors Jonathan Winter and Justin Mankin and earth and planetary sciences professor Erich Osterberg and earth science graduate student Janelle Wargo GR’25 published a study in the Journal of Hydrometeorology in which they found that droughts in the northeastern United States have become less frequent and less intense.
The researchers studied rainfall data in the region dating to 1901 and found that droughts since 1980 have been 59% less frequent and 19% less intense than the period from 1901 to 1980, even though anthropogenic climate change is expected to increase drought frequency and intensity.
In 2025, much of the northeastern U.S. experienced a record-breaking drought. New Hampshire Gov. Kelly Ayotte issued a state-wide burn ban from Sept. 22, 2025, to Oct. 29, 2025, leading to the cancellation of the annual Homecoming bonfire that fall. The last bonfire to be canceled due to drought was in 1963.
The Dartmouth sat down with Winter, the study’s lead author, to discuss drought, climate preparedness and what the study means for future Homecoming bonfires.
The average person’s understanding of climate change likely involves a warmer, drier climate. What is it about the Northeast that leads to such a different reality?
JW: Warmer climate is homogeneous; everywhere is getting warmer. Whether it gets wetter or drier really depends on the background conditions. Basically, we have this race between how fast we’re losing water from the surface and how fast we’re getting water from the atmosphere. So far, the Northeast has received more than we’ve lost. The increase in precipitation has outpaced the increase in water loss to the surface, which we call evapotranspiration.
Your paper describes how temperature-driven decreases in evapotranspiration and higher precipitation lower the chance of drought. Is it likely the current balance will be disrupted, leading to more, intense drought in the future?
JW: One thing that we make very clear in the paper is we only look at historical changes in drought, and I can’t tell you in the future whether there might be this inflection point where that rate of the increase of loss of water from the surface outpaces the rate of the increase in precipitation.
The paper does not say that drought in the Northeast is over. The Northeast has always had drought, and will continue to have drought. It’s just if you look at the statistics of how intense and frequent our drought has been over the past 120-some-odd years.
The severe drought in 2025 led to a statewide burn ban and the cancellation of the Homecoming bonfire. What might your findings mean for the future of the Homecoming bonfire at Dartmouth?
JW: My findings would suggest that there’s less of a chance that we would have to cancel the bonfire in the future. But I think those types of drought events are pretty rare to start with. Clearly 2025 is part of this record of the observed decreases — it could be that next year we have to cancel the bonfire because it’s dry. But, if I’m looking over the 120-year record, we could still see decreases. It’s tough to separate the individual events from the overall statistical record of looking over the long term. But what my findings would suggest is there’s less of a chance that it should be canceled now, than there would be if you went back pre-1980.
What about agriculture and private wells? How might they be influenced by precipitation patterns that you projected?
JW: What the findings say is that farmers are less vulnerable now to drought than they have been historically. Again, that doesn’t alleviate the fact that a lot of farmers took a big hit in 2025. There always has been drought and there always will be drought in the Northeast. They just seem to be less frequent and intense. Wells should be less vulnerable because you have less drought.
How do you hope this study will be applied? Do your findings change how the region should be thinking about climate change preparedness?
JW: I think that’s a great question for towns, municipalities and states. It’s possible that it can affect prioritization of what kind of climate hazard you’re preparing for, but I would never recommend that we shouldn’t prepare at all for drought. The balance of how each organization decides it’s going to adjust to climate change — that really has to be based on the people that they’re tasked with preparing. In a resource-constrained world, thinking through where best to place our resources, this could be one piece of evidence that comes into the equation.
What’s the next piece of the puzzle for you? What subject would you like to see examined further?
JW: This gets a little bit at the details of the study. On the drought front, we use this relatively straightforward metric that uses temperature and precipitation rainfall to assess drought — the Palmer Drought Severity Index. We also looked at some soil moisture data. Whereas the metric PDSI that we use showed decreasing drought, the soil moisture data showed unchanged drought. One of the things that I would be interested in following up on with this study is figuring out why those two metrics are telling us different stories.
This interview has been edited for clarity and length.
