Korea had 8.8 tropical nights in July, a record high figure since the relevant tally began in 1973, government data showed Friday.
A tropical night is defined by a minimum temperature of 25 degrees Celsius or higher from 6 p.m. to 9 a.m. the next day.
According to the Korea Meteorological Administration, the average number of tropical nights in July between 1991 and 2020 stood at 2.7 days. However, the figure dramatically rose threefold last month to 8.8.
In July alone, Seoul had 11 tropical nights, which is higher than the nationwide average. Gangneung in Gangwon Province experienced three “ultra-tropical night” phenomenons where the nighttime temperature remains above 30 degrees Celsius. Previously Gangneung had ultra-tropical nights only twice, once in 2008 and again in 2017.
Such high temperatures are continuing for August. Seoul's morning lows on Friday was 28.2 degrees and those of Gangneung, 31.4 degrees.
As of Friday, heat wave warnings or advisories were issued in 180 out of 183 municipalities nationwide. Only Ongjin County in Incheon, the five West Sea islands and the mountainous area of Jeju Island have not received heatwave alerts.
The number of days when heat wave warnings or advisories were issued in July stood at 7.2, far exceeding the average of 4.9 days during the same period between 1991 and 2020. However, it is less than the 16.9 days from 2018, which was Korea's hottest summer on record.
However, as the country is experiencing unprecedented heat this summer, experts expect the record of 26 consecutive tropical nights from 2018 to be broken.
The Ministry of Interior and Safety raised the heat wave response level to "serious," the highest within its four-tier system.
The scorching heat is resulting in an increase in the number of people experiencing heat-related illnesses.
According to the ministry Friday, a total of 1,195 people were treated for a heat-related disease between May 20 and July 31.
The figure is similar to last year's 1,208 during the same period.
The country has also seen damage to livestock from the extreme heat.
From June 11 to Aug. 1, nearly 250,000 livestock animals, including around 20,000 pigs and 230,670 poultry, died due to heat. The aquaculture industry has also seen 3,500 flatfish deaths.