Jeju Island is having its longest-ever monsoon season, with rain falling on the island almost every two days.

According to the Korea Meteorological Administration on Monday, the island province started its rainy season June 10, making Monday its 48th day. That is the highest number since 1998, when the island’s monsoon season lasted 47 days.

The national weather agency expects the island’s summer rainy season to wrap up soon, possibly after Tuesday.

The length of a monsoon season is calculated based on how long a region stays under heavy rainclouds with high humidity. Jeju Island’s shortest so far was in 1973, lasting just one week.

Over the past 48 days, Jeju Island has seen rain on 29 days, the second-highest number of rainy days in any monsoon season in the island’s history. If the rain continues Tuesday as expected, the island will set another record.

Despite the record length of the monsoon season, not much rain has fallen on the island this year. From the start of this year’s rainy season to 10 a.m. Monday, Jeju Island received a total of 517.75 millimeters of rain, only the 11th-highest figure on record for the island.

The weather agency explained that the rain was concentrated in the island’s mountainous areas and southern regions, with the northern parts receiving relatively little rain.

Once the monsoon season comes to an end -- which could happen as late as early next month -- scorching heat is expected, the agency added. The KMA said there will be many days in August when hot temperatures accompany high humidity.

By Ko Jun-tae (ko.juntae@heraldcorp.com)