Could wildfires become our new normal?

Mark Ashton, a professor of silviculture and forest ecology at Yale University, expects climate change to amplify the underlying conditions responsible for the high numbers of wildfires, “but in an erratic way.” Overall we should expect wetter weather in New England, “with larger stronger rain events but also interspersed with drier periods.”

Ashton also said the region’s forests have a history — including past land clearance for and subsequent recovery from agriculture, and the impact from waves of diseases, insects and plants — that makes them “very predisposed to drought.”

“The forests are very ready to burn and burn hot,” he said.

In the latest flare-up, scores of firefighters from multiple communities on Tuesday worked to douse the blaze toward the southern perimeter of the Blue Hills near Houghton’s Pond, one of at least 20 that burned throughout the state this week. Also on Tuesday, crews fought a blaze in Boxford State Forest that consumed more than 100 acres. The fire had forced the closure of a stretch of Middleton Road, and authorities were imploring people to call 911 if they saw fire within 200 feet of their property.

Fires this week were also reported on the North Shore, in Boston’s southern suburbs, and in Western Massachusetts. Last week, the Lynn Woods Reservation was closed because of a blaze that covered more than 400 acres.

A similar story is playing out in Rhode Island, where there have been more than three dozen wildfires since the start of October — more than nine times as many as last fall.

Globe meteorologist Ken Mahan said much of New England might see anywhere from 0.75 inches to 1.5 inches of rain between Thursday and Saturday, and the more mountainous parts may even see some snowflakes.

“Our region would need to see some persistent wet weather over the span of a few weeks to months in order to shake off the drought that has drained water supplies,” Mahan said. “The good news is that this rain should absolutely alleviate brush and wildland fires.”

As of last Sunday, it is now the driest fall on record for Boston, passing the record set in 1914, Mahan said.

Stephen Pyne, an emeritus professor at the school of life sciences at Arizona State University, said the clear “underpinning phenomenon” for the wildfires is the drought.

“That doesn’t make fires happen, but it may make more fires reach a state where they need to be responded to,” he said.

Pyne also considered that global warming may be playing a part in fostering conditions where more wildfires occur. But, he said, there are typically dry spells in the Northeast in the spring and autumn. Climate change, he said, tends to exaggerate or extend what already exists.

Another factor in the spread of wildfires is the amount of land that could burn and how that land is managed, Pyne said.

The Blue Hills fire started around 1 p.m. Monday, and nearly 90 firefighters spent the day fighting it. Crews had back-burned areas of the large forest, a strategy that includes lighting patches of ground aflame so that when the fire line reaches it, there is nothing left to burn.

“Fight fire with fire,” Milton Fire Chief Chris Madden said. Across the street, the forest floor was covered in a fine ash that looked like sand.

By Tuesday night, the Milton fire had ripped through 41 acres of forested reservation, and was only about 50 percent contained, according to fire officials.It closed down part of the public space to passersby.

Firefighters faced an added challenge: the hilly, wooded terrain, which makes it difficult to get water to the blaze. The firefighters were using several of the reservation’s popular trails to either access the fireline or use as lines of containment.

“We’re operating 30 feet into the black, which is basically everything that’s already burned. We’re going to wet down 30 feet in,” Madden said. “Anything farther in, we’re not going to touch because it’s just too dangerous.”

Dead and burning trees pose a serious hazard to firefighters because they can fall over without warning, and a burned-out root system makes that even more likely, according to the state’s Department of Fire Services. Earlier this month, three Massachusetts firefighters were injured by falling trees and limbs, and the state office is “hearing of frequent near misses.”

The ongoing drought and the fallen leaves have created a tinderbox, Madden said.

“The fuel load right now is tremendous,” he said.

Nearly all of the wildfires sparking up across the state are caused by human activity, officials have noted, and are in many instances preventable. Blazes have been sparked by people burning yard waste, outdoor cooking and heating, fireplace ashes, hot engines and gasoline from power equipment such as lawn tractors, and careless disposal of smoking materials.

“We can’t stress this enough: the extreme fire behavior we’re seeing this season poses a grave risk to people — residents and firefighters alike,” said Jake Wark, a spokesperson for the state’s Department of Fire Services. “This is no time to be using a fire pit or burning leaves, because these fires will grow out of control and every firefighter battling a preventable wildfire is one who can’t respond to a structure fire, car crash, or medical emergency.”

Christopher Gavin of the Globe staff contributed to this report.

Danny McDonald can be reached at [email protected]. Follow him @Danny__McDonald. Emily Sweeney can be reached at [email protected]. Follow her @emilysweeney and on Instagram @emilysweeney22.