Korea Astronomy and Space Science Institute releases astronomical data on the 2026 chuseok full moon

A winning entry from the 34th Korea Astronomy and Space Science Institute Astrophotography Contest. © Choi Sang-ju [Korea Astronomy and Space Science Institute]
A winning entry from the 34th Korea Astronomy and Space Science Institute Astrophotography Contest. © Choi Sang-ju [Korea Astronomy and Space Science Institute]

This year's chuseok full moon will rise at 5:34 p.m. Friday.

According to astronomical data the Korea Astronomy and Space Science Institute released Tuesday, the chuseok full moon will rise at 5:34 p.m. Friday in Seoul and reach its highest point in the sky at 11:31 p.m. the same night.

The moment when the moon sits directly opposite the sun and becomes perfectly round — known as the full moon phase — will occur at 1:49 a.m. Sunday, two days after chuseok. As a result, the moon visible on chuseok night will not be perfectly full, appearing slightly less than complete on its left side.

There are two main reasons the chuseok full moon is not always perfectly round. First, the exact time of the new moon on the first day of the lunar month affects the phase of the moon when it rises on the 15th day. Second, the moon's elliptical orbit means the time it takes to travel from the new moon position to the full moon position is not constant.

Moonrise times in other major cities are: 5:24 p.m. in Ulsan, 5:25 p.m. in Busan, 5:27 p.m. in Daegu, 5:32 p.m. in Daejeon, 5:33 p.m. in Sejong, 5:34 p.m. in Gwangju and 5:35 p.m. in Incheon. Sunrise and sunset times for other regions are available on the institute's astronomy and space knowledge information website.


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