Morning lows of 11–20 C, afternoon highs of 24–30 C; dense fog expected inland in Gangwon and elsewhere

Strong swells along east, south coasts and Jeju Island through Wednesday; gale advisories in effect

Rain forecast for Chuseok holiday; full moon viewing unlikely this year

Visitors seek shade at Haneul Park in Mapo-gu, Seoul, on Sunday as mild early-autumn weather continues. [Yonhap]
Visitors seek shade at Haneul Park in Mapo-gu, Seoul, on Sunday as mild early-autumn weather continues. [Yonhap]

Wednesday marks the autumnal equinox — the fourth seasonal division of autumn, when day and night are of equal length — and skies will be mostly clear across the country. Temperature swings of up to 15 degrees Celsius or more between day and night signal a pronounced change of season. Rain is forecast for the latter half of the upcoming Chuseok holiday weekend, threatening both travel safety and hopes of viewing the full moon.

According to the Korea Meteorological Administration, Wednesday will be mostly sunny nationwide as a high-pressure system moves northeast from the northern East Sea, though Gangwon Province's east coast and mountain areas, the North Gyeongsang Province east coast and Jeju Island will see occasional heavy cloud cover. The five West Sea islands may receive brief showers of less than 5 millimeters from morning through midday.

Morning lows will range from 11 to 20 C and afternoon highs from 24 to 30 C, near or slightly above seasonal averages. However, as cold air moves in around the equinox, the daily temperature range across most inland areas will widen to around 10 to 15 C — and in parts of inland Gangwon Province the gap may exceed 15 C — making careful attention to health during the seasonal transition particularly important.

Dense fog with visibility below 1 kilometer is expected from the early hours of Wednesday through mid-morning in eastern Gyeonggi Province, inland and mountainous areas of Gangwon Province, North Chungcheong Province, North Jeolla Province, inland South Jeolla Province, inland North Gyeongsang Province and western inland South Gyeongsang Province, coinciding with the start of the Chuseok homebound travel rush. Drivers should slow down, particularly on roads near rivers and lakes where visibility will be even more limited.

Coastal safety risks are also elevated. Gale advisories are in effect for the southern East Sea, the open waters of the South Sea and waters around Jeju Island, where winds of 8 to 15 meters per second and waves of 1.5 to 3.5 meters are expected through early Wednesday. Strong swells along the east coast, the South Gyeongsang Province southern coast and the Jeju Island shoreline could wash over breakwaters and coastal roads through Wednesday, and the public is urged to stay away from the water's edge.

Meanwhile, weather conditions are expected to deteriorate as the Chuseok holiday weekend progresses. Rain will begin along the northern Gangwon east coast on Thursday night, then spread to the Gangwon and North Gyeongsang east coasts in the early hours of Friday — Chuseok day itself — before expanding to central regions late that night. Clouds and rain will make it difficult to see the full moon across most of the country on Chuseok night. On Saturday, the day after Chuseok, rain will spread nationwide, and drivers heading home should be prepared for wet road conditions.

※ This article was produced using AI technology based on data from the Korea Meteorological Administration.


silverpaper@heraldcorp.com