DAEJEON — When will this autumn's foliage be at its best?
The Korea Forest Service released its 2026 Peak Autumn Foliage Forecast Map on the 22nd, covering the timing of peak fall colors at major forests and arboretums nationwide.
This year's first autumn leaves were recorded on Sept. 14 at the forest genetic resource reserve on Mount Jeombong, based on citizen observations. According to the forecast, leaves will begin turning in earnest in the northern mountains of Gangwon State in early October, with peak color — defined as 50% of leaves turned — expected nationwide in late October.
By species, maples and oaks are both forecast to peak on Oct. 31, and ginkgo trees on Oct. 30.
By region, the peak is expected to begin at Mount Seorak and spread gradually to central and southern areas. Forecasts by mountain are Oct. 20 for Mount Seorak, Oct. 28 for Mount Songni, Nov. 4 for Mount Naejang and Nov. 6 for Mount Halla. That is about 0.8 days later than the average peak over the past five years.
Since 2009, the Korea Forest Service and the Korea National Arboretum have been building long-term plant phenology observation records together with public arboretums across the country, while the National Institute of Forest Science has continuously collected weather data for forest areas through its mountain weather observation network.
The agency plans to link the data with wide-area forest observations from agricultural and forestry satellites, drawing on field observations, weather data and satellite imagery together to improve the accuracy of foliage forecasts and to provide information that helps the public see how climate change is altering seasonal cycles in forests.
"We will provide accurate forecast information based on plant phenology observation data accumulated over a long period," said Park Young-hwan, head of the Korea Forest Service's forest environment protection division. "We hope people will use the foliage forecast map to enjoy the autumn colors."
