Korea saw a record number of tropical nights this summer when the temperature did not drop below 25 degrees Celsius after dark.
Seoul saw 21 tropical nights this summer as of Saturday, the second largest number since weather observation began in 1907, the Korea Meteorological Administration said on Sunday.
The most happened in 1994 with 36.
Between Aug. 1 and 17 this year there were 16 tropical nights in Seoul, or every night except one.
Jeonju and Gangneung saw the most tropical nights at 28 and 25 since 1994. Jeju (43), Daegu (33) and Daejeon (20) also saw record numbers of tropical nights.
"Hot and moist air continued to flow into the country from the south under the influence of particularly strong North Pacific anticyclones this year," Weatherman Huh Jin-ho said. "This increases humidity in the air, which prevents the heat from dissipating at night and keeps temperatures high all day."
The tropical nights will abate in the central region this week. The heat wave which has brought temperatures of over 35 degrees almost every day will ease a little in southern parts in the latter part of this week, the KMA forecast.