In December 2025, Jeju's weather stations recorded monthly mean temperatures of 8.8 to 11.0 °C, and foreign visitor estimates rose around Christmas and New Year.
In the December 2025 records, Jeju's weather was milder than in January 2026, and the days that stood out for foreign visitor estimates were around Christmas and New Year.
Is Jeju worth visiting in December?
The records on this page point to a mild island rather than a harsh one. In December 2025, monthly mean temperatures at four Jeju weather stations ranged from 8.8 to 11.0 °C. Foreign visitor estimates for Jeju that month were 25% below the mean of the twelve months ending December 2025. Those are observations from one year, not a forecast for December 2026.
Whether that suits a trip depends on what you want from it. If the plan is coastal walking, markets and short days outdoors, the weather records below are the relevant evidence. If the plan is built around Christmas Eve or New Year's Eve, the visitor estimates show those days stood apart from an ordinary December.
How cold is Jeju in December, and does it snow?
The table gives the four Korea Meteorological Administration ASOS stations on the island. The mean daily minimum is the monthly mean of each day's lowest temperature. It is not the lowest temperature of the month.
| Station | Monthly mean temperature, December 2025 | Mean daily minimum, December 2025 |
|---|---|---|
| Jeju (184) | 9.6 °C | 6.1 °C |
| Gosan (185) | 9.9 °C | 6.6 °C |
| Seongsan (188) | 8.8 °C | 4.3 °C |
| Seogwipo (189) | 11.0 °C | 7.1 °C |
Seongsan was the coolest of the four on both measures in December 2025, and Seogwipo the warmest. Snow-day counts exist on this page for two stations only. The Jeju station recorded 3 days with snow in December 2025 and the Seogwipo station recorded 2. This page has no snow-day figure for Gosan or Seongsan, and no weather figure for the slopes of Hallasan.
Daylight in December
Days are short. For one calculator point in Jeju, the Korea Astronomy and Space Science Institute calculator gives sunrise at 07:19 and sunset at 17:25 on December 1, 2026, a day length of about 606 minutes. On December 31, 2026 the same point has sunrise at 07:37, sunset at 17:35 and a day length of about 597 minutes. Other parts of the island can differ by a minute or more.
What do the foreign visitor estimates show?
The figures here are KTO DataLab estimated daily foreign visitors. They are not tourist arrivals and not unique people, and they are not added across days, regions or administrative levels. Jeju City and Seogwipo City are parts of the Jeju figure, so the three rows below overlap.
| Region | Mean per day, December 2025 | Mean per day, twelve months ending December 2025 | Difference | Days covered |
|---|---|---|---|---|
| Jeju | 29,655 | 39,704 | 25% below | 31 of 31 days in December 2025; 365 of 365 days in the twelve months |
| Jeju City | 24,110 | 30,996 | 22% below | 31 of 31 days in December 2025; 360 of 365 days in the twelve months |
| Seogwipo City | 13,322 | 19,585 | 32% below | 31 of 31 days in December 2025; 360 of 365 days in the twelve months |
In December 2025 the estimates ran below each region's own twelve-month mean, and the gap was widest in Seogwipo City. That says December 2025 was lower than the year as a whole. It does not say why.
Which holidays fall around a December trip?
Korea's Christmas holiday is December 25. In 2026 it falls on a Friday, and there is no substitute holiday. December 31, 2026 is a Thursday and not a legal holiday. New Year's Day, January 1, 2027, is a Friday holiday.
Two neighbouring holiday calendars overlap the New Year period. Japan's administrative-office holidays ran from December 29, 2025 to January 3, 2026, and run from December 29, 2026 to January 3, 2027. China's Yuandan holiday ran from January 1, 2026 to January 3, 2026. This page has no Chinese Yuandan dates for 2027.
The window estimates below compare the daily average across each holiday window with the mean of the four nearest same-weekday non-holiday observations before December 24, 2025.
| Region | Christmas Eve and Christmas Day, December 24 to December 25, 2025 | New Year's Eve and New Year's Day, December 31, 2025 to January 1, 2026 |
|---|---|---|
| Jeju | 32,501 per day, 18% above the baseline of 27,600 | 38,632 per day, 40% above the baseline of 27,600 |
| Jeju City | 25,310 per day, 19% above the baseline of 21,242 | 30,054 per day, 41% above the baseline of 21,242 |
| Seogwipo City | 15,627 per day, 25% above the baseline of 12,544 | 19,595 per day, 56% above the baseline of 12,544 |
Each window had 2 of 2 days paired with the baseline. The New Year window was higher than the Christmas window in all three regions, and Seogwipo City showed the largest rise in both. The New Year window overlapped both the Japanese year-end break and the Chinese Yuandan holiday. This page cannot show whether either one caused the rise.
What should I do in Jeju in December?
The visitor and weather records say nothing about attractions, so this section is general background. Jeju is known for Hallasan and its national park, the crater at Seongsan Ilchulbong, the coastal Olle walking routes, the waterfalls around Seogwipo and the markets of Jeju City. This page has no opening hours, prices or event schedules for any of them.
One way to use the records is to build days around the light. With sunrise at about 07:19 and sunset at about 17:25 on December 1, 2026 for the same calculator point in Jeju, outdoor stops fit best in the middle of the day, and it is worth planning indoor stops for after sunset. A sample outline for a few days:
- East coast: Seongsan, where the December 2025 mean daily minimum was 4.3 °C, the lowest of the four stations.
- Jeju City: markets and city streets, with indoor stops to plan for after sunset.
- South coast: Seogwipo, where the December 2025 station records were the warmest of the four.
Is the island suitable with kids? This page has no figure on that. The weather and daylight records above are what it can offer a family deciding on dates.
December or January?
January 2026 was colder than December 2025 at all four stations, on both measures.
| Station | Monthly mean temperature, January 2026 | Mean daily minimum, January 2026 |
|---|---|---|
| Jeju (184) | 5.9 °C | 3.0 °C |
| Gosan (185) | 6.0 °C | 3.4 °C |
| Seongsan (188) | 5.1 °C | 1.1 °C |
| Seogwipo (189) | 7.4 °C | 3.6 °C |
Snow days rose too. The Jeju station recorded 8 days with snow in January 2026, against 3 in December 2025, and the Seogwipo station recorded 6, against 2.
The foreign visitor estimates for January 2026 were at similar levels to December 2025, each against its own twelve-month baseline. Jeju was 26% below, Jeju City 24% below and Seogwipo City 33% below, with monthly means of 29,559, 23,869 and 13,078 per day. The January baselines cover the twelve months ending January 2026, not December 2025. So the choice between the two months rests more on the weather records than on the visitor estimates. The holiday windows are what set the end of December apart.
Sources
- Korea Tourism Organization DataLab regional visitor estimates (data.go.kr dataset 15101972)
- Gov.cn, State Council General Office notice on 2026 holiday arrangements
- Beijing Municipal Government, reposted State Council General Office notice on 2026 holiday arrangements
- Korea Astronomy and Space Science Institute, sunrise and sunset time calculator
- Japan e-Gov Law Search, Act on Holidays of Administrative Organs (Act No. 91 of 1988), Article 1
- House of Representatives of Japan, Act on Holidays of Administrative Organs (Act No. 91 of 1988), enactment text
- Korea Law Information Center, Regulations on Holidays of Government Offices
- Korea Astronomy and Space Science Institute, Special Day Information API (data.go.kr 15012690)
- Korea AeroSpace Administration, announcement of the 2026 Wollyeok Yohang (calendar outline)
- Korea AeroSpace Administration, announcement of the 2027 Wollyeok Yohang (calendar outline)
- Korea Meteorological Administration, ASOS daily observations (data.go.kr 15059093)
- KMA Open MET Data Portal, ASOS daily data lookup
- KMA Open MET Data Portal, observing station information
Checked on October 10, 2026.