South Korea Braces for Cloudy Weather, Unhealthy PM2.5, and Coastal Swells

Korea will be largely cloudy tonight and tomorrow, with scattered light rain possible along the central western coast through tomorrow morning. Inland areas, including the Gangwon region’s mountains, may see brief showers in the afternoon.

Air quality is expected to worsen, with PM2.5 levels deemed unhealthy in the central region and, from tomorrow afternoon, in the southern regions as well. This could affect outdoor plans and health for sensitive groups.

Morning temperatures will be around 0 to 6 degrees Celsius nationwide, with Seoul near 4°C. Daytime highs are forecast to reach about 10 to 16°C, similar to today or slightly cooler, and a notable day-to-night temperature swing is expected to persist in the coming days.

Sea conditions look relatively calm overall, with wave heights of 0.5 to 2 meters on all seas. The East Coast and Jeju Coast may see higher swells, which could affect coastal travel and shipping lanes.

Why this matters beyond Korea: South Korea is a major producer of semiconductors, electronics, and other high-tech goods whose global supply chains power U.S. industries. Weather and air quality can influence factory operations, worker health, and transport reliability, potentially impacting product timelines and prices. Rough seas along the East Sea and around Jeju can affect container and bulk shipments, with knock-on effects for global markets.

For readers unfamiliar with the locale: Seoul is the capital and largest city. Gangwon Province is a mountainous northeastern region known for winter sports and national parks. Jeju is a volcanic island located south of the peninsula. The East Sea refers to the body of water between Korea and Japan. PM2.5 denotes ultra-fine particulate matter linked to health risks.

Meteorological updates will continue to monitor these conditions, and travelers or logistics operators should stay tuned to official briefings for any changes in rain, air quality, or sea states.