Jeju Island's Mount Halla saw its first frost of the year arrive eleven days earlier than in 2017.
According to the Jeju branch of the Korea Meteorological Administration(KMA) on Saturday, the season's first frost was reported at the mountain's Witse Oreum volcanic cone situated at one-thousand-668 meters above sea level and also at the azalea field at an altitude of nearly one-thousand-490 meters.
Mount Halla is the highest point in South Korea.
Morning lows on Saturday recorded minus three-point-seven degrees Celsius at the azalea field and minus three at Witse Oreum.
Frost was also reportedly observed on Friday at the top of Mount Halla but the KMA used the Saturday observation in its official record.
The agency said that temperatures below zero were reported on various parts of the mountain on Saturday morning, with frost and freezing temperatures forecast at higher altitudes.
Hikers are advised to take precautions when visiting the mountain.