This photo shows visitors to the National Museum of Korean Contemporary History in Seoul on Sunday, with Gyeongbokgung and Cheong Wa Dae in the background. — THE KOREA HERALD/ANN Photo

SEOUL — Amid an intense heat wave in South Korea that shows no signs of abating, a government estimate suggested Sunday that the number of suspected heat-related deaths has reached 11, almost triple the number last year.

From May 20 until Saturday, the South Korean government's daily estimate showed that 11 deaths were suspected to be heat-related, compared to four in the same period last year.

In the latest incident, a pedestrian in his 50s died at around 3pm Friday after he collapsed in Seongnam, Gyeonggi Province.

By region, Gyeonggi Province saw three deaths, while South Chungcheong Province and North Gyeongsang Province reported two deaths each. Seoul, Busan, North Jeolla Province and South Gyeongsang Province, each had one heat-related death, according to the estimate by the Korea Disease Control and Prevention Agency.

The government also estimated that over 2,300 people experienced heat-related illnesses in the same period. Ninety-eight cases were reported on Saturday alone.

With the mercury rising above 37 degrees Celsius on Sunday, the Korea Meteorological Administration's forecast suggested that the heat wave, defined as successive days when the high tops 35°C, will likely last until Thursday.

South Korea is currently under the influence of a double high-pressure system, as the country's Ministry of Interior and Safety on Friday estimated that over 40 per cent of the nation's territory would see highs of 35°C over the next three days.

The same day, the Central Disaster and Safety Countermeasures Headquarters entered Level 1 emergency operations — the lowest of the three-tiered system.

On Sunday, heat wave advisories or warnings were in effect in 180 out of 183 weather zones across the country.

In Seoul, daily highs are forecast to reach 35°C or higher through Thursday, then begin to dip below 35°C starting Friday due to increased cloud cover.

Seoul will also endure tropical nights, as nighttime temperatures will stay above 26°C throughout the week. The daily lows in the capital are forecast to be around 27°C on Monday and 28°C on Wednesday.

The heat wave, coupled with heavy rain in mid-July, has caused significant crop damage, resulting in a spike in food prices.

The KMA estimated that South Korea experienced 9.5 days of heat wave conditions from June 1 until last Tuesday, which was the second-highest number recorded since 1973.

Meanwhile, according to the Interior Ministry as of Sunday morning, South Korea had enough capacity to cover the 81.5 gigawatts of electricity demand during the peak hours expected Sunday evening. — THE KOREA HERALD/ANN