Monday was the hottest yet this summer with the temperature in Hongcheon, Gangwon Province climbing to 36-point-one degrees Celsius.

Afternoon highs were 35-point-two degrees in Uiseong, North Gyeongsang Province, and 34 in Yangpyeong, Gyeonggi Province. The mercury hit 33-point-two in Seoul and in Jecheon, North Chungcheong Province.

The Korea Meteorological Administration says the hot weather was because of foehn, or the easterly winds growing hotter and drier as they blow over the mountains.

The weather agency says temperatures of over 30 degrees will continue until the monsoon season officially starts Thursday.