The Korea Meteorological Administration said on the 22nd in its three-month outlook that temperatures this summer are expected to be above average. Its analysis suggests that all three months from June to August are likely to be hotter than usual.
Temperatures from June to August are forecast to be higher than average. (Source: Korea Meteorological Administration)
The probability outlook points in one direction. The chance of above-normal temperatures is highest in June and July at 60% each, and 50% in August. Rainfall is expected to be above average in June and July, and close to normal in August. Sea surface temperatures around Korea are also forecast to remain above average from June to August.
Rainfall from June to July is expected to be mostly above average, while August is forecast to be close to normal. (Source: Korea Meteorological Administration)
The KMA attributed this pattern to a high-pressure circulation developing to the east of Korea.
The circulation is expected to increase the inflow of warm tropical air and, as high pressure strengthens aloft, boost solar radiation, pushing temperatures higher. The increase in rainfall was analyzed to have been influenced by above-normal snowfall over the Tibetan Plateau in spring, which strengthened the upper-level trough over East Asia.
Summer records broken two years in a row
This forecast draws attention because it comes alongside observational records from recent years.
According to KMA data, the average summer temperature nationwide in 2025 was 25.7 degrees Celsius, the highest since nationwide observation networks were expanded in 1973. The previous year, 2024, also set a record with an average summer temperature of 25.6 degrees. In other words, the record set one year was surpassed the next.
In the summer of 2025, the average daily maximum temperature was 30.7 degrees, the highest on record, while the average daily minimum temperature was 21.5 degrees, the second highest on record.
When record-breaking temperatures continue year after year, statisticians interpret that as a trend. The KMA’s forecast that this summer will also be hotter than average means it sees little chance of this upward trend reversing this year.
The meaning of the terminology is also changing. Severe midsummer heat has long been described as “abnormal heat.” The term implies an exception outside the normal range. But as summers above average repeat every year, experts in and outside meteorology increasingly argue that heat waves should be seen not as a highly variable anomaly, but as a constant that must be assumed each year.
1.5 degrees, the structural background to heat on the Korean Peninsula
The heat on the Korean Peninsula cannot be explained apart from global warming.
The World Meteorological Organization said in a global climate status report released last year that the 2024 global average temperature was about 1.55 degrees Celsius above pre-industrial levels.
1.5 degrees is the benchmark agreed by the international community in the 2015 Paris Agreement as the limit for temperature rise. It was the first time in recorded history that the annual average exceeded this threshold.
The WMO explained that, in terms of the long-term trend, the warming level is still 1.34 to 1.41 degrees, and has not yet reached 1.5 degrees. Still, it is clear that humanity has come very close to that threshold.
Global warming makes summers on the Korean Peninsula harsher in two ways. One is rising temperatures; the other is changing precipitation patterns. The warmer the atmosphere, the more water vapor it can hold.
That moisture then concentrates and falls in specific places at specific times. The KMA’s forecast for above-average rainfall in June and July and the possibility of localized torrential rain is a typical result of a warmer atmosphere.
Heat waves and heavy downpours are not separate disasters, but two phenomena split from the same cause, according to the climate science community.
The sea surface temperature around Korea from June to August is forecast to be higher than average. (Source: Korea Meteorological Administration)
The ocean is sending the same signal. The KMA forecast that sea temperatures around Korea this summer will be above average, and that sea surface temperatures in the central and eastern tropical Pacific are likely to gradually rise, making a transition to El Niño more probable.
Warmer seas supply more heat and moisture to the atmosphere, increasing the variability of summer weather. It is a structure in which both land and ocean temperatures rise at the same time.
The same pattern is being observed globally. The WMO has estimated an 86% probability that at least one year between 2024 and 2028 will set a new all-time high temperature. This means that repeated hot years are no longer an exception but a highly probable scenario.
From warnings to adaptation infrastructure
As heat waves become a recurring annual condition, the focus of response is shifting from short-term preparedness to structural adaptation.
The KMA said it will begin operating a new severe heat warning and tropical night advisory system this summer, and will introduce an emergency disaster text alert system for torrential rain at disaster levels.
The measures reflect the judgment that heat and heavy rain now threaten lives. However, warning systems merely alert people to danger; they do not reduce the scale of the risk itself. That is why what comes after the warning remains a task for society and individuals.
Heat damage does not fall equally on everyone. Elderly people living in homes without air conditioning, workers who spend long hours outdoors, and those with limited mobility are exposed to danger first.
This is why heat response must be treated not only as a weather issue but also as a welfare and labor safety issue. Institutional measures such as cooling shelters for vulnerable groups and guaranteed rest breaks at outdoor worksites must work together if warnings are to translate into real reductions in harm.
The urban structure itself is also a major issue. City centers covered with asphalt and concrete act as urban heat islands, absorbing heat during the day and releasing it at night. This is why tropical nights can be more dangerous than daytime heat.
When more shade is created through street trees, urban waterways and wind corridors that reduce heat are added, and roofs and exterior walls that reflect sunlight are introduced, the felt environment of a city changes even under the same heat wave. To reduce recurring urban flooding each year, drainage and retention facilities that temporarily store rainwater and release it gradually need to be redesigned not for past average rainfall, but for increased rainfall levels.
These measures are typically classified as “climate adaptation.” They are paired with “mitigation,” which aims to slow the pace of warming by reducing greenhouse gas emissions.
Mitigation takes a long time to show results, but adaptation-oriented design can reduce damage from the coming summer immediately. The two pillars must move together, and that has become the basic direction of climate policy.
The KMA’s summer outlook is, in form, a routine seasonal forecast. But beyond the numbers lies the reality that summers above average are being repeated every year.
The question of hot summers has shifted from whether they will happen to how prepared society is when they do.
As we respond to this summer’s heat, we must also design cities and institutions for the next summer in parallel. The outlook once again underscores that point.