Children play in a water fountain at a park in Busan as heat wave warnings continue, Tuesday. Yonhap

Korea faces a prolonged and intense heat wave, along with a rise in tropical nights, as the monsoon season ended nationwide around Saturday, according to the Korea Meteorological Administration (KMA), Tuesday.

The weather agency said as of Saturday, this year's monsoon season brought an average of 472 millimeters of rainfall nationwide, 1.3 times higher the usual average of 356.7 millimeters seen between 1991 and 2020.

It said a subtropical anticyclone will impact the country, with the likelihood of a typhoon affecting the region diminishing. However, the KMA also noted that the arrival of midsummer heat does not necessarily mean the end of heavy rainfall.

"A possibility of torrential rain remains due to low-pressure troughs moving south, coupled with high levels of water vapor," an official from the KMA said.

As midsummer approaches, many regions are expected to experience extended heat waves, with midday temperatures ranging from 30 to 36 degrees Celsius nationwide through Aug. 9. On Tuesday, temperatures in the Gyeongsang provinces and areas along the east coast already reached 35 degrees Celsius, the KMA said.

This trend has led to predictions that the country may see the longest stretch of tropical nights on record. Tropical nights are defined as periods when the temperature stays above 25 degrees Celsius between 6 p.m. and 9 a.m. the following day.

Korea had an average of 7.1 tropical nights nationwide from June 1 to July 28, the highest number recorded since 1994.

From 1991 to 2020, the average number of tropical nights during June and July was 2.7 days. Historically, June typically saw no tropical nights, while July saw an average of 2.7 days.

The highest number of tropical nights recorded from June to July was in 1994, with 8.6 days, followed by 7.1 days in 2018.

The KMA attributed this year's increase in tropical nights to persistent high temperatures and humid southerly winds along the edge of the North Pacific anticyclone, which kept nighttime temperatures elevated.

The first tropical night of this year was recorded in Gangneung, Gangwon Province, on June 10, six days earlier than last year.

As the heat wave continues, the KMA warned of potential health risks, including heat-related illnesses, and urged the public to take necessary precautions.