Heat wave warnings were issued for some 30 cities nationwide on Thursday, including Seoul and Daegu, following the passing of Typhoon Neoguri.

The warning is issued if the temperature is expected to remain above 33 degrees Celsius.

The Korea Meteorological Administration said Typhoon Neoguri brought heat and humidity to the Korean Peninsula, which eventually generated a post-typhoon heat wave across the country.

The agency issued the year’s first heat wave warning for Seoul on Wednesday. The temperature in Seoul was 32.6 degrees Celsius as of 1 p.m. on Wednesday, and 32.1 as of 2 p.m. on Thursday.

Some 15 cities in Gyeonggi Province, including Ansan, Suwon, Gwangmyeong and Seongnam, as well as eight cities in Gangwon Province, including Chuncheon, Wonju, and Yeongwol, received warnings from the state agency on Thursday.

The agency also issued the warning for Seoul and Daegu, as well as five cities in Chungcheong and Gyeongsang provinces including Yesan, Gongju and Gyeongsan.

Seoul and a number of other regions nationwide have also experienced “tropical nights” since Wednesday, defined by nighttime lows above 25 degrees Celsius. Tropical nights are known to occur the most at the end of monsoon season, which usually falls in July in Korea.

The agency predicts the temperature in Seoul will be 33 degrees Celsius on Friday, and 34 degrees Celsius in Daegu.

“It is important to drink enough water,” an official from the agency said. “Also, try not to spend too much time outside during the day.”

By Choi He-suk (dyc@heraldcorp.com)