The unusual heat wave that started last week will drag on till mid-September, the Korea Meteorological Agency said Thursday.

The KMA said the daytime high across the nation is expected to soar over the weekend and reach at least 35 degrees Celsius. The daytime high in Seoul hit 30 degrees Celsius as of Thursday afternoon.

While monsoon rain is likely to descend on the Southern part of the peninsula, humidity will also be high, as well as the discomfort index, weather forecasters warned. 

The heat has led to the deaths of four elderly and more than 960,000 livestock including pigs and chickens within a month, mainly in Jeolla and Chungcheong provinces.

In Busan, a 53-year-old man was found dead Sunday inside his car after sleeping overnight in it.

Health authorities encouraged those above 70 and those who work outdoors to stay hydrated and avoid going outside from noon to 5 p.m.

According to the World Meteorological Organization, 2016 will be the hottest year on record.

A WMO report released last week said that carbon dioxide levels, the main catalyst for global warming, have reached 407 parts per million, compared to the previous average of 400 ppm.

It said that the first six months of 2016 set a record as the warmest consecutive months in history.

By Kim Da-sol(ddd@heraldcorp.com)