Minnesota’s dry autumn has been a boon to farmers but is raising concern among foresters, who warn of potential fire danger along the state’s northern border.

While September was dry throughout the state, the northern tier and the Arrowhead region are in moderate drought conditions. Southwestern Minnesota is also very dry, with parts of Rock County classified as severe drought areas.

“Our fuels are drying out. Grasses and trees are becoming easier to ignite,” said Caleb Grunzke, a meteorologist with the National Weather Service in Chanhassen.

Duluth has been extremely dry, Grunzke said. The area has gotten only about 15 inches of precipitation this year, about 10 inches less than average. The Boundary Waters area also is much drier than usual, he added.

In the Twin Cities, precipitation has been close to average so far, running only about six-tenths of an inch below normal for the year.

The dry weather has been great for farmers, who suffered through a very wet harvest season last year. Across the state, the harvest is proceeding rapidly.

According to the U.S. Department of Agriculture, the corn harvest is 18 days ahead of last year’s pace. The soybean harvest is 12 days ahead of last year and sunflowers are 25 days ahead. Half of the state’s sugar beet crop has been harvested; last year at this time, with machinery struggling in muddy fields, only 17% of the beets were out of the ground.

But with October historically a key month for wildfires, the dry autumn weather has foresters “cautiously concerned,” said Casey McCoy, wildfire prevention supervisor for the Forestry Division of the Minnesota Department of Natural Resources (DNR).

“We’re getting into that time of year when we enter our second fire season,” McCoy said. “The recipe is coming back together again — the combination of low humidity, elevated winds, maybe some more high temperatures.”

After the first frost, he said, grass and leaves start to die: “When they start to go dormant, the chance for a fire moves up. Those smaller, finer fuels are … the ones that change moisture content most rapidly.”

Experts are watching areas of northwest Minnesota that have peat soil, such as in the Baudette area, said Travis Verdegan, DNR predictive services coordinator. If peat were to ignite, say through a lightning strike, it could burn for months, he said.

“I’m going to be watching that through the winter and see where we are in the spring,” he said.

McCoy noted that October was when the great Peshtigo wildfire took place — on Oct. 8, 1871, to be exact. The fire burned 1.2 million acres in Door County, Wis., and all around Green Bay — the body of water, not the city. Between 1,500 and 2,500 lives were believed lost.

The Peshtigo fire isn’t well remembered because it happened on the same day as the great Chicago fire that burned down much of the city. But foresters are well aware of it and think of it when October rolls around.

“We still know that we can have large fires under relatively moderate conditions,” McCoy said. “A lot of folks in the fire section won’t truly relax until there’s snow on the ground.”