It was forecast to be extremely hot again on the 6th, a day before Ipchu, the solar term that means the start of autumn. In particular, Seoul could set an unprecedented record of 40 degrees.
On Thursday the 6th, the morning low is expected to be 21–27 degrees, and the daytime high 30–39 degrees. In Seoul, the morning low is forecast at 27 degrees and the daytime high at 39 degrees.
A daytime high of 39 degrees is record heat. Since modern meteorological observations began in October 1907 in Seoul (Seoul Weather Observatory standard), the highest temperature was 39.6 degrees on Aug. 1, 2018. The second highest was 38.4 degrees on July 24, 1994. There has been only one instance of exceeding 39 degrees.
Given that the average absolute error of the Korea Meteorological Administration's high-temperature forecast is about 1 degree, an unprecedented heat of "40 degrees in Seoul" could appear on the 6th.
Expected lows and highs for major cities outside Seoul are Incheon 26 and 38, Daejeon and Gwangju 26 and 37, Daegu 26 and 36, and Ulsan and Busan 26 and 33.
A heat emergency warning, the highest heat advisory, has been issued for 31 land weather advisory zones, including 30 districts in the capital area and Gwangyang in South Jeolla and Gwangju. Most other regions are also under heat advisories.
On the 5th, a heat advisory was reissued for most of Yeongdong in Gangwon. With easterly winds blowing in the lower atmosphere near the surface, the west of the Taebaek Mountains was extremely hot due to the foehn effect, while the east was relatively cooler; but as the easterlies did not turn into rain and clear skies kept strong sunlight in place, Yeongdong in Gangwon is said to be experiencing heat again.
On Friday the 7th, the morning low is forecast at 22–27 degrees and the daytime high at 31–39 degrees, similar to the 6th.
Over the weekend, as clouds and rain move into some areas, on Saturday the 8th the morning low is expected to be 22–27 degrees and the daytime high 27–36 degrees.
On Sunday the 9th, temperatures are expected to be 21–26 degrees and 26–34 degrees, somewhat lower than before, but still high compared with average temperatures.
After that, at least through Liberation Day, a heat wave is expected to continue, with the apparent temperature rising to 35 degrees or higher inland and 33 degrees or higher in other regions.
Typhoon Dolphin, the 13th of the season, which had raised hopes of ending the heat wave, has a very high chance of making landfall south of Shanghai, China, after passing Okinawa, Japan.
Dolphin passed 940 kilometers east of Okinawa, Japan, at 3 p.m. on the 5th and is expected to continue moving west with little change in direction to make landfall south of Shanghai, China, on the 10th in the afternoon.
The prevailing view is that the heat will not end even after Dolphin passes. It is still early August, when the North Pacific high-pressure system is at its strongest, so even if the pressure system reorganizes under the typhoon's influence, Korea is likely to remain under the influence of the North Pacific high.
On the 6th, ozone concentrations in the capital area, South Chungcheong, North Jeolla, and South Jeolla are expected to thicken to "bad" levels in the afternoon.
From the night of the 6th, swells will flow into the Jeju coast, and waves high enough to spill over rocky shores or breakwaters will pound the shore, so people should avoid going there if possible.