Monsoon shifts north, leaving Korea sweltering under intense summer heat

Visitors navigate the wet paths of the Imjingak Tourist Complex in Paju, Gyeonggi Province, Tuesday. Yonhap

An early retreat of the monsoon front has left Korea with one of its shortest rainy seasons in recent memory, exposing much of the country to sustained heat and oppressive nighttime temperatures.

The Korea Meteorological Administration said Thursday that this year’s monsoon ended on June 26 in Jeju, a week earlier than usual and half its normal length at just two weeks — making it the island’s second-shortest rainy season on record. The southern part of the mainland saw a similarly brief spell, with the monsoon ending on July 1 after only 12 days. While rainfall is expected to remain limited, meteorologists say the rainy season may not yet be over for Seoul and parts of the upper mainland.

While the exact dates remain subject to change, the broader pattern is clear: An anomalously strong North Pacific subtropical high-pressure system has displaced the monsoon front to the north, leaving southern Korea largely dry, with intensifying heat conditions.

Korea’s rainy season, known locally as “jangma,” typically stretches from late June through late July or early August, delivering much of the nation’s annual rainfall.

A farmer takes a drink from an ice-cold water bottle while working in the fields of Goryeong County, North Gyeongsang Province, Wednesday, with the region under a heatwave alert. Yonhap

In Seoul, July is typically the wettest month of the year, averaging about 415 millimeters of rain over 16 days. This year, however, forecasts show no significant rainfall through at least July 8, with the capital expected to remain mostly cloudy, hot and humid.

Korea’s experience is not unique.

In Japan, regions at similar latitudes to Jeju, such as Kyushu and Okinawa, have also seen their rainy seasons end early.

Around the world, 2025 is shaping up to be among the hottest years to date. In May, global surface temperatures were 1.10 degrees Celsius above the 20th-century average — the second highest for the month since record-keeping began.

According to the World Meteorological Organization, there is a 70 percent likelihood that global warming will temporarily breach the 1.5 degrees Celsius benchmark by 2030, a development that could accelerate the frequency and intensity of extreme weather.

Across the continents, nations are grappling with the consequences. Portugal and Spain recorded historic temperatures exceeding 46 degrees Celsius, and Europe has seen unprecedented “super tropical nights” with overnight lows above 30 degrees Celsius.

People are silhouetted against the setting sun on a street in Sanaa, Yemen, Wednesday. Yemen is in the grip of a severe heatwave, with temperatures ranging between 32 and 40 degrees Celsius across most parts of the country, the nation's meteorological service reported. EPA-Yonhap

In Central Asia, a March heatwave brought temperatures up to 10 degrees Celsius above average. The United Arab Emirates recorded its hottest May on record, while in Africa’s Sahel region, temperatures soared above 45 degrees Celsius, with deadly consequences for public health and agriculture.

In Korea, the number of annual heatwave days and tropical nights has surged over the past decade. In 2022, Seoul recorded its first June tropical night since 1907 — a trend that has continued for four consecutive years.

In 2024, Korea recorded 30.1 days of heat waves — the second most in its history — while tropical nights reached an unprecedented 24.5 days. Experts caution that even small increases in global temperatures amplify the frequency, severity and duration of extreme heat, with profound implications for public health, infrastructure and food systems.

“As a result of human-induced climate change, extreme heat is becoming more frequent, more intense. It’s something we have to learn to live with,” Clare Nullis, spokesperson for the World Meteorological Organization, said at a press briefing in Geneva, Wednesday.