2025 ranked as S. Korea’s second hottest year on record

According to the Korea Meteorological Administration (KMA), the country’s average annual temperature reached 13.7 degrees Celsius last year. This was 0.8 degrees lower than the record high set in 2024 and equal to the figure recorded in 2023, placing 2025 jointly as the second hottest year since systematic weather observations began in 1973.

The temperature was also 1.2 degrees higher than the long-term average of 12.5 degrees recorded between 1991 and 2020. With the exception of February and May, every month last year recorded above-average temperatures. June and October each set new records for the highest monthly average temperature.

The KMA attributed the extended heat to the North Pacific High, which developed earlier than usual and remained stronger for a longer period. Its proximity to the country allowed hot and humid air to persist, pushing temperatures higher.

Nationwide heat wave days, defined as days with temperatures reaching at least 33 degrees Celsius, averaged 29.7 last year, nearly three times the long-term average of 11 days. Tropical nights, when temperatures remain above 25 degrees Celsius overnight, totaled 16.4 days, compared with the historical average of 6.6 days.

Notably, Daegwallyeong, a mountainous area in Gangwon Province at an elevation of 772 meters, recorded a temperature of 33.1 degrees Celsius on July 26. This marked the first heat wave observed at the location since monitoring began there in 1971.

Meanwhile, the average sea surface temperature around the country reached 17.7 degrees Celsius, the second-highest level recorded in the past decade. Annual rainfall totaled 1,325.6 millimeters, roughly in line with the long-term average of 1,331.7 millimeters.

Previously, it was reported Belgium records the fourth warmest year on record in 2025.