Snow is seen at Seoraksan Mountain in Gangwon Province on Wednesday. (Seoraksan National Park Office)

A rare mid-May warning of heavy snow was issued Wednesday over mountainous areas in northern Gangwon Province.

The warning went into effect at 7:20 p.m. as snow, which had started shortly beforehand, was forecast to continue into Thursday morning, accumulating up to 7 centimeters in highland and other mountain areas of northern Gangwon.

A heavy snow warning is issued when snowfall accumulation is expected to reach five centimeters or more within a 24-hour period.

It marks the first mid-May heavy snow warning since 1996 although the mountainous Gangwon region typically experiences mild snow in May.

The last heavy snow warning issued in May was in 2021, which was on the first day of the month.