Electricity meters are seen in this photo taken from a residential building in Seoul, Sept. 9. Yonhap

Korea's peak electricity demand hit a new record in September, as the scorching summer heat extended into the autumn season, data showed Wednesday.

The country's peak power demand last month averaged 78 gigawatts, a 6 percent increase from a year earlier, according to the Korea Power Exchange, marking the highest level for any September on record.

The increase was driven by higher electricity consumption for air conditioning due to the heat wave that persisted throughout the month.

The figure was just below the peak of 80.5 gigawatts recorded in July during the height of the summer heat wave.

Korea's meteorological agency reported that the average daily low temperature in September reached 20.9 degree Clesius, the highest since the agency began compiling data in 1973.

Experts warn that households may face higher electricity bills, as the summertime billing system, which is designed to ease financial burdens, only applies from July to August.

Meanwhile, the state-run Korea Electric Power Corp. has been seeking to raise electricity rates to address volatility in the global energy market. (Yonhap)