The unseasonably balmy weather throughout the Northeast in recent weeks, however pleasant, has stirred some of the driest drought conditions in recent memory, leaving New Jersey and Connecticut vulnerable to hundreds of wildfires.

In New Jersey, 377 wildfires have burned over 628 acres since Sept. 15, a jump from 26 wildfires with only about seven acres consumed over the same period last year. State authorities have not reported any injuries from the fires.

In Connecticut, where Gov. Ned Lamont has declared a state of emergency, there have been 84 wildfires since Oct. 21, an increase from five over the same period in 2023. The largest fire this fall, a 127-acre blaze about 15 miles south of Hartford, injured six people and killed one firefighter.

Human activity, whether accidental or intentional, causes 99 percent of wildfires in New Jersey, said a spokesman for the state’s Forest Fire Service. Officials in New Jersey are investigating whether any of the fires in the state were the result of arson; authorities in Connecticut did not immediately respond to a request for comment about what started its fires. A burn ban is in place for much of Connecticut and all of New Jersey.

“We have never experienced conditions like this,” said Bill Donnelly, chief of the New Jersey Forest Fire Service. “It’s so dry, the fires are burning down into the ground and are continuing to smoke.”

Having multiple wildfires in the Northeast might seem surprising for a region where rainfall averages are increasing and flooding poses a constant threat. But climate change can produce unpredictable weather patterns, said David Robinson, the New Jersey state climatologist and a geography professor at Rutgers University.