August has longest streak of 10.3 tropical nights nationwide on average

As of Sunday, South Korea had an average of 10.3 tropical nights nationwide, setting a new record for August. Simply put, people have tossed and turned due to nighttime heat every three days since this month began. The national average of tropical nights for August turned out to be the highest ever since the current weather observation system was put in place in 1973. By definition, a tropical night is a summer night with a minimum temperature of 25 degrees Celsius and above from 6 p.m. to 9 a.m. the next morning.

The nationwide average of 10.3 tropical nights this August almost triples that of a normal year. According to an analysis of data provided by the Korea Meteorological Administration on Sunday, the average tropical nights from August 1991 to 2020 were only 3.5. Even with one more week left until the month ends, the country already broke the record of 9.4 tropical nights in August 2018, thereby setting a new high in six years.

Experts agree that this summer will be recorded as having more tropical nights than any other summer season in 51 years. After all, the country had the largest number of tropical nights in July this year - around triple that of a normal July period (2.8 nights) - since related data were first collected. With 19.2 tropical nights recorded as of Sunday since the beginning of this year, the country sets a new record almost every day after surpassing 16.8 nights and 16.6 nights in 1994 and 2018, respectively. Tropical nights ended on Saturday night in Seoul, where the minimum nighttime temperature was 24.9 degrees Celsius – after a streak of 34 days. Although only a difference of 0.1 degrees saved it from a 35th sleeplessly hot night, tropical nights are likely to come back, given that weather forecasts say that the minimum temperature will go up to 25 degrees Celsius and above around this Friday.


Sung-Jin Park psjin@donga.com