Due to the arrival of an early heat wave, electronics makers are stepping up production of air conditioners. Samsung and LG both saw second-quarter operation rates at their plants soar on-year.

Since mid-April, Samsung's plant in Gwangju has been operating its production lines at full capacity. LG also started operating production lines for air conditioners at its plant in Changwon, South Gyeongsang Province in late April, more than two weeks earlier than last year.

Unseasonably high temperatures seem to be the main reason for the soaring demand. The mercury topped 30 degrees Celsius in Seoul in mid-May, while a heat advisory was issued for Gyeonggi Province, making it the hottest mid-May since 1932.

"Production volume almost doubled compared to last year," said a Samsung spokesman. "At the current pace, sales of air conditioners will likely surpass last year's total of over W3 trillion."

"We already produced 3.32 million air conditioners in the first quarter and we are expecting to set a new record in terms of production volume, replacing the previous record of 12.1 million units set in 2013," an LG spokesman said.