While outside temperatures may feel unseasonably warm, Carbon County is steadily approaching the peak of its fall foliage season.

The county’s normal peak is in mid-October, but a string of warm weather has led to a slight delay in the arrival of red, orange and yellow leaves.

“We’ve really been missing out on those really cool and crisp nights, and that really tends to stall the foliage,” said Ryan Reed, who compiles the Department of Conservation and Natural Resources’ weekly foliage report.

While weather has been slightly warmer than usual during the month of September, shorter days mean the transition is underway.

As of last week, no local counties were classified as reaching “peak color” by DCNR.

This week, Monroe County and higher elevation areas of Carbon, like Hickory Run State Park, could be approaching their foliage peaks this week.

Carbon, Schuylkill, Lehigh and Northampton counties are still categorized as “approaching peak color” this week, according to DCNR.

The warm weather has affected what experts thought would be a strong season for fall color. With no droughts in the late summer, trees had plenty of water to produce healthy leaves.

The early autumn weather hasn’t been as ideal for producing peak color. A Penn State expert said in an article published last week that warm October weather could lead to a less vibrant display.

“Due to the wet summer, this was shaping up to be a banner year for the foliage, but we need the weather now to cooperate and cool down,” said Marc Abrams, a professor of forest ecology and physiology. “With unusually warm weather predicted until the middle of October, I expect that will delay and somewhat diminish fall colors.”

Daylight hours and temperature are the main factors affecting the timing of the change to red, orange and yellow. Shorter days mean less light for plants, which breaks down the chlorophyll pigment which gives them their green color. In mid-october, each day is about two minutes shorter than the previous one.

“The trees know it’s time to give up on photosynthesis because its growing season is coming to an end, the sunlight is waning and it doesn’t make sense to waste energy producing it,” Reed said. “The other pigments underneath are now able to see the light of day, and it’s able to show those beautiful oranges and reds.”

Red leaves can be found on trees like red maple, cherry, dogwood, oak and ash; while yellow leaves are found on beech, aspen, birch, poplar and some maples.

While DCNR maps foliage by county, forests can peak at different times based on the trees making them up. Reed said it’s possible that there could be peak foliage just over a ridge, or a short drive away.

Visitors will have plenty of options for outdoor festivals in the area, as well as state parks like Beltzville, Lehigh Gorge, Hickory Run, Tuscarora, and Locust Lake.

“If people want to go for a quick drive to some beautiful public land, it’s right there at arm’s length for a lot of people,” Reed said.