Tropical Nights and Heat Waves: Increasing Trends in Extreme Weather Events

Recently, South Korea has been experiencing record-breaking tropical nights and heat waves every summer. A tropical night is defined as a night with a minimum temperature of 25°C or higher, while a heat wave refers to a day with a maximum temperature of 35°C or higher. This is interpreted as the impact of climate change due to global warming.

According to data from the Korea Meteorological Administration, the number of tropical nights has significantly increased since the 1990s. In Seoul, the average annual number of tropical nights has increased fivefold from 2.4 days in the 1970s to 11.7 days in the 2010s. Notably, in 2016 and 2018, Seoul recorded 31.6 and 24.1 days of tropical nights, respectively, setting new records.

The number of heat wave days has also been steadily increasing. The average annual number of heat wave days, which was only 1.1 days in the 1960s, increased to 6.3 days in the 2010s. In 2018, record-breaking heat waves continued across the country, with Seoul experiencing 16.6 days and Daegu 24.9 days of heat waves.

Frequent occurrences of tropical nights and heat waves have adverse effects on various aspects, including health, agricultural damage, and power supply imbalances. In particular, the risk of heatstroke is higher for the elderly and children who are vulnerable to heat. In response, the Korea Meteorological Administration issues public behavioral guidelines when tropical nights and heat waves are expected.

Abnormal weather patterns due to climate change are expected to become increasingly frequent. It is now crucial to implement both greenhouse gas reduction measures and adaptation efforts at the individual and community levels.