Tiger Hill and the Northwest River in Sebago, Maine. Credit: Courtesy of Jerry Monkman, ecophotography.com via Loon Echo Land Trust

Leaf peepers, start your engines.

One of Maine’s happiest traditions of fall, trips into the North Maine Woods to observe the changing of the colors of the state’s leafy trees, will likely have to ramp up this week thanks to some unseasonably cold weather and an early frost, according to the Maine Fall Foliage Report and its spokesperson, Gale Ross.

According to the report, the leaves of northwestern- and northeastern-most Maine, from Eustis and Greenville diagonally to a point just north of Houlton along the Maine coast, are well underway on their colorful journey from green to the vibrant yellow, orange and red hues of fall.

“It’s really about the weather going forward that determines the impact on the season. We’ve seen those shortened sunny days, followed by cool and in some cases cold nights, including an early frost, this past week which has accelerated the color change,” Ross said on Wednesday. “The fall colors have emerged rapidly. Colors will accelerate daily as the entire state starts going toward peak conditions in October.”

Issued weekly by the Maine Department of Agriculture, Conservation and Forestry, the report tracks the color progress of fall foliage across the state using a network of observers, including Maine forest rangers and forest pathologists.

“Right now forest rangers are reporting high ― 70 percent — color in the higher elevations of Maine, Aroostook and the northern portion of Somerset County. The rest of the state is showing moderate to low color change,” Ross said.

The report is updated on Wednesday afternoons, typically starting mid-September and running through October, until most of the leaves have fallen from the trees or faded to brown. The full reports include color-coded maps that divide the state into different zones and are available at mainefoliage.com.

Northern Maine, or zones 6 and 7 on the report map, will reach peak conditions the last week of September into the first week of October. The rest of the state’s progression of color will start occurring from north to south in mid-October, according to the report.