South Korea’s 2026 monsoon season is expected to begin around the usual time and last about a month.
Based on climate normals from 1991 to 2020, the rainy season typically starts on Jeju Island and moves north through the southern and central regions. Using that pattern, the monsoon is forecast to begin around June 19-21 on Jeju, June 23-25 in the south, and June 25-27 in central areas including the Seoul metropolitan region.
The end of the season is also expected to follow the typical timeline: around July 20 on Jeju, around July 24-25 in the south, and from around July 26 through late July in central regions. The overall duration is projected at about 30-31 days, broadly in line with the commonly cited average of about 31-32 days.
The outlook is based on past weather data, and actual start and end dates could differ by about one to three days depending on factors such as the expansion of the North Pacific high-pressure system, the position of the stationary front and shifts in atmospheric flow. With climate change increasingly affecting rainfall patterns, some experts have also stressed that preparedness should focus less on the length of the season and more on rainfall intensity.
Experts say that even if the monsoon period is similar to normal, rainfall may come in a different form, with more “downpour-type” events that dump heavy rain in a short time rather than steady rain over many days. That can increase damage even when total rainfall is similar.
Claims circulating on social media that it “rains nonstop for a month” are largely exaggerated, experts say. Breaks in rain and clear days are common during the monsoon, and continuous rainfall is not typical in meteorological terms. Still, repeated bursts of intense local rain can make it feel as if it is raining all the time.
Weather statistics also show that atmospheric instability can bring “guerrilla downpours” into early August even after the monsoon ends. In recent years, stronger localized heavy rain has sometimes occurred after the rainy season, underscoring the need for summer disaster preparedness.
Experts say people should be ready for summer hazards such as flooding, landslides and river overflows, since damage can rise sharply if rainfall concentrates in a short period even when the monsoon’s overall timing is near normal.
The projection is a statistical estimate based on the past 30 years of weather data, and conditions may change as the season develops. The Korea Meteorological Administration’s short- and medium-range forecasts should be checked regularly.
* This article has been translated by AI.
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