Women wearing coats walk along Deoksugung Stonewall Road in Seoul, Sunday. Morning temperatures are expected to drop below freezing in Seoul as chilly air spreads across Korea this week after an unusually warm fall, according to the Korea Meteorological Administration. Yonhap

Morning temperatures in Seoul are expected to drop below freezing on Monday as cold air spreads across Korea following an unusually warm fall.

Temperatures in the city are forecast to fall to minus 2 degrees for the first time this winter, with temperatures in some other regions expected to drop to as low as minus 6 degrees, the Korea Meteorological Administration (KMA) said Sunday.

A cold wave advisory has been issued for cities across the country, including Busan, Daejeon, Suncheon and Jeju. The advisory is issued when the daily low falls below minus 12 degrees Celsius for more than two consecutive days or when the temperature drops by more than 10 degrees Celsius in a single day, reaching below 3 degrees Celsius.

On Monday, temperatures in the capital are expected to reach their lowest point at 8 a.m., rising to 6 degrees Celsius in the afternoon before dropping back to near-freezing levels later in the day.

Meanwhile, early morning temperatures will hit minus 6 degrees Celsius in Inje county and minus 5 degrees Celsius in Cheorwon county in Gangwon Province and minus 3 degrees Celsius in Dongducheon, Gyeonggi Province, according to the KMA.

Due to a cold front from Siberia, morning temperatures are expected to hover near freezing throughout the week, the weather agency added.

This sudden change in temperature comes after unusually warm weather in October and early November.

According to the KMA, the average temperature during October was 16.1 degrees Celsius, the second-highest since it began collecting data in 1973. On Nov. 2, temperatures in Seoul reached 25 degrees Celsius during the daytime for only the fourth time since 1907.