Compare the climate averages
These are 1991–2020 climate averages, not a forecast for your visit. The daily high and low columns average many days over that period; they are not limits on how hot or cold a particular day can become. Precipitation is the average monthly total.
| City | Monthly mean (°C) | Average daily high (°C) | Average daily low (°C) | Average high–low difference (°C) | Monthly precipitation (mm) | Relative humidity |
|---|---|---|---|---|---|---|
| Busan (부산) | 17.9 | 22.5 | 14.5 | 8.0° | 79.6 | 62.7% |
| Daegu (대구) | 16.2 | 22.0 | 11.4 | 10.6° | Not available in this dataset | Not available in this dataset |
| Gangneung (강릉) | 15.6 | 20.3 | 11.5 | 8.8° | 113.9 | 61.5% |
| Gyeongju (경주) | 14.8 | 21.6 | 9.3 | 12.3° | 108.2 | 75.1% |
| Incheon (인천) | 15.3 | 19.9 | 11.4 | 8.5° | 51.1 | 66.7% |
| Jeju (제주) | 18.6 | 21.6 | 15.7 | 5.9° | 95.1 | 66.4% |
| Seoul (서울) | 15.0 | 20.2 | 10.6 | 9.6° | 52.2 | 61.8% |
| Sokcho (속초) | 15.1 | 19.5 | 10.8 | 8.7° | 87.9 | 65.6% |
Source: Korea Meteorological Administration, 1991–2020 climate normals. A missing value means it is unavailable in the dataset used here, not that the city has no rain or that no other climate record exists. The selected table does not cover every Korean city.
Plan for mild afternoons and cool evenings
October often suits walking and sightseeing, with lower average humidity and precipitation than midsummer. It is still a month with changing weather, not a guarantee of clear skies.
Mornings and evenings can be noticeably cooler than the afternoon, particularly inland. Bring a jacket and layers, and use a mountain forecast for hiking rather than a nearby city's temperature.
Rain and strong wind remain possible. Check current warnings even though typhoons are less common than in late summer; a monthly average is not a probability for an individual trip.
Check the two early-October holidays
National Foundation Day is 3 October, and Hangeul Day, which celebrates the Korean alphabet, is 9 October.
In 2026, the holidays create long weekends on 3–5 October and 9–11 October. In 2027, the corresponding periods are 2–4 October and 9–11 October, including substitute days.
Popular routes and accommodation can be busy around these dates. Reserve essential journeys when sales open and check the particular venue's holiday arrangements. Do not assume every train sells out or that an entire week between holidays will be quiet.
Chuseok, the autumn harvest holiday, falls in September in 2026 and 2027. Check its date again for another year because it follows the lunar calendar.
Follow the development of autumn colour
Higher and more northerly areas often change earlier than lower or more southerly ones, but tree species and local weather also affect the timing. Different parts of the same mountain can be at different stages.
Use the Korea Meteorological Administration's foliage observations when available, alongside current park information. A previous year's forecast is not a promise for your visit.
Seoraksan is a popular autumn destination, but viewing foliage does not require every visitor to undertake a demanding hike. Choose a route that fits your ability and check access, weather and any reservation requirements.
City colour can develop through late October and November. Avoid treating “October for mountains, November for cities” as a rule without exceptions.
Confirm festival details
Autumn events include the Jinju Namgang Yudeung Festival, known for lanterns along the river, and the Andong International Maskdance Festival. Check the organiser's dates, venues and ticket conditions for the edition you intend to attend.
Some events span two months or change their usual timing. For fireworks and other large gatherings, confirm the current programme before arranging accommodation around an assumed date.
Pack for the route you choose
Bring comfortable shoes, rain protection and a layer for cooler starts or evenings. A mountain outing requires suitable footwear, warmer layers and enough daylight for the return.
Check sunset and trail access times, and do not let a crowded viewpoint delay you beyond a safe return time. For city sightseeing, alternate outdoor walks with indoor stops if the weather changes.
