South Korea braces for cold spell with snow, rain and bad air quality

The Korea Meteorological Administration warned that Thursday will be a chilly day across the inland areas, with morning temperatures dipping below freezing in parts, before a rebound to the low to mid-teens in many regions. Seoul is forecast to reach about 13°C by afternoon.

Across the country, morning low temperatures are expected around 1°C in Seoul and Incheon, with slightly higher readings in central and eastern regions (Chuncheon near -1°C, Gangneung around 4°C). Daytime highs range from about 8°C in the east to around 13°C in many western and southern cities, including Seoul, Jeonju, Gwangju, Busan and Jeju, which are all forecast to reach 11–13°C.

Rain or snow is set to affect parts of the eastern coastline and southern areas. From early morning into the afternoon, precipitation is possible along the Gangwon east coast and its mountains, the eastern coastline of North Gyeongsang, and parts of Busan, Ulsan and eastern Gyeongnam. In the afternoon and evening, showers could move into Chungbuk and the eastern parts of Jeolla and other southern regions.

Late-day drizzle is possible on Jeju Island between 6 p.m. and midnight, with a trace to less than 0.1 millimeter in some areas. From the afternoon into the evening, Gangwon’s mountains could see accumulating snow, and by the mid-to-late afternoon into evening hours, additional rain or snow may occur in central regions.

Overall precipitation totals are forecast to include 5–20 mm in parts of the Gangwon east coast and mountains, with around 5–10 mm in Busan and Ulsan, and lighter amounts in other areas such as Chungbuk, eastern Jeolla, and eastern Jeonbuk. Snow accumulation of 5–15 cm is expected in the Gangwon mountain areas.

Road conditions could deteriorate where rain or snow occurs. Reduced visibility and slippery surfaces, including possible icing, mean travelers should exercise caution, especially along inland routes and the eastern coasts.

Air quality is also a concern. The forecast calls for “bad” fine dust (PM2.5) in Seoul, Incheon, southern Gyeonggi, Chungcheong, and parts of Jeollabuk and Jeollanam-do, with other regions at normal levels. Some northern parts of Gyeonggi, western Gangwon, Daegu, and parts of North and South Gyeongsang may also experience elevated levels in the morning, with conditions improving in some eastern areas later in the day and through the afternoon.

Why this matters for U.S. readers: Korea is a key global supplier of semiconductors and electronics, and weather and air-quality events can disrupt manufacturing shifts, logistics, and worker health in urban hubs like Seoul and Busan. Prolonged cold spells and precipitation can affect energy demand, commuting patterns, and port operations that connect Asian supply chains with the United States. In addition, air-quality episodes influence health and labor productivity in a major regional economy, a factor in U.S.–Korea environmental policy discussions and regional security considerations tied to technology industries and critical infrastructure. For markets, any domestic disruption in Korea’s tech heartland can have ripple effects on global supply chains, pricing, and timelines for electronics components and related goods.