Korean Chunbun Brings Large Day-Night Temperature Swing, Mild Afternoons Ahead

Thursday marks Chunbun, the vernal equinox in Korea’s solar calendar, when day and night are almost equal. In this period, daytime temperatures rise sharply while nights remain cool, producing a large diurnal temperature swing.

This morning in Seoul began around 2.5°C, with daytime temperatures forecast to reach about 14°C. Forecasters say temperatures will continue to climb into early next week, bringing unusually mild afternoons for the season.

Residents are advised to dress in layers and be prepared for chilly mornings and evenings despite the milder daytime warmth, as the big day-night temperature gap remains a feature of spring.

Skies are expected to be clear across the country, and air quality is described as good. Winds along the East Sea coastline are likely to be stronger through the afternoon.

Current readings show Seoul at about 3.4°C and Daejeon around 1.2°C, while daytime highs are projected to be 14°C in Seoul, 15°C in Gangneung and Cheongju-Daejeon, and around 17°C in Daegu and Changwon. Jeju Island is forecast to see rain on Sunday.

Why this matters beyond Korea: South Korea is a major producer of semiconductors and display panels, so local weather can influence manufacturing schedules and global electronics supply chains. A mild but unsettled spring can affect energy demand and consumer behavior in a tech-driven economy, with potential knock-on effects for suppliers and markets in the United States. Strong winds along Korea’s eastern coast can also impact shipping routes and port operations in the region, with relevance for American exporters and multinational manufacturers.

Context for readers: Chunbun is one of Korea’s 24 solar terms used in the lunisolar calendar to mark seasonal change. The Korea Meteorological Administration provides official forecasts; the described conditions reflect typical early-spring patterns on the Korean Peninsula.