Pack layers for an October trip to Korea. In the 2021–2025 observations used here, Seoul’s average daily high was 20.6°C and its average daily low was 11.8°C. Busan’s corresponding figures were 23.3°C and 15.5°C, while Chuncheon’s were 19.8°C and 9.4°C. A city, a date within October and an early start can all change what you need to wear. These figures are calculated from Korea Meteorological Administration observations.
The tables compare the five completed Octobers from 2021 through 2025. They are a recent sample for planning, not 30-year climate normals and not a forecast for October 2026. Use them to choose flexible clothing, then use a forecast to decide what to wear on a particular day.
What do the temperature figures mean?
Each city represents one KMA observation station. We averaged the daily highs and daily lows for October 1–31 in each of the five years: 155 days per city, with no missing temperature values in this dataset. Values are rounded to one decimal place.
An average daily high is not the highest temperature ever recorded that month. An average daily low is not a guaranteed overnight minimum. Individual days can be warmer or colder. These are station measurements, so a city row also does not describe every mountain, island or neighbourhood around it. The linked city names open the official daily-observation pages; change the year to inspect the other years in the sample.
How warm are Seoul and the central and northern cities?
| City | Average daily high, °C | Average daily low, °C |
|---|---|---|
| Seoul | 20.6 | 11.8 |
| Incheon | 19.8 | 12.6 |
| Suwon | 20.7 | 10.9 |
| Chuncheon | 19.8 | 9.4 |
| Gangneung | 20.6 | 12.8 |
| Daejeon | 21.4 | 11.0 |
| Sejong | 20.8 | 10.8 |
| Cheongju | 21.2 | 12.1 |
Calculated from October 2021–2025 KMA daily observations. These are five-year averages, not forecasts.
For Seoul, Incheon and Suwon, a removable outer layer gives you options between daytime sightseeing and an evening return. Chuncheon had the lowest average daily minimum of these 16 stations. If your itinerary includes an early departure or a long outdoor stop there, consider an extra insulating layer. For Daejeon, Sejong and Cheongju, the gap between the average highs and lows also supports packing more than a single outfit for all hours.
Those are clothing suggestions based on the table, not dress rules. Your activity and comfort matter. If you are planning day trips into outer Gyeonggi, use the destination forecast rather than assuming that Seoul’s temperature applies everywhere. That linked itinerary was written for Chuseok; its holiday opening notices do not establish October hours.
How do southern cities and Jeju compare?
| City | Average daily high, °C | Average daily low, °C |
|---|---|---|
| Busan | 23.3 | 15.5 |
| Daegu | 22.0 | 11.9 |
| Gwangju | 22.4 | 13.0 |
| Ulsan | 21.5 | 13.1 |
| Jeonju | 22.1 | 12.2 |
| Changwon | 22.7 | 13.8 |
| Pohang | 21.5 | 14.1 |
| Jeju | 23.4 | 17.4 |
Same October 2021–2025 calculation. Jeju refers to the Jeju station, not the whole island or Hallasan.
Busan and Jeju had higher average daily lows than Seoul in this sample. A lighter combination may suit an active daytime visit there, with an outer layer available for later. Daegu, Gwangju, Jeonju and Changwon still show a substantial difference between average highs and lows; being farther south does not mean you can ignore mornings and evenings.
For Gangneung, Pohang, Ulsan and other coastal stops, check wind as well as temperature before choosing your outer layer. This study did not calculate wind averages. A city temperature table is also not a substitute for a mountain forecast if your plans move inland or uphill.
Does the start of October differ from the end?
The sample shows a clear reason to check your exact dates. Here are average daily lows for the first ten days and last eleven days of October, pooled across the same five years.
| City | October 1–10 low, °C | October 21–31 low, °C |
|---|---|---|
| Seoul | 14.8 | 9.3 |
| Chuncheon | 12.9 | 5.9 |
| Busan | 18.2 | 13.2 |
| Jeju | 19.4 | 15.2 |
Calculated from 50 early-month days and 55 late-month days per station in 2021–2025. These averages are not predictions for those dates in 2026.
For a late-October trip with outdoor mornings, a sweater or fleece that fits under a jacket gives more flexibility than packing only for the monthly average high. For an early-October itinerary, removable layers let you adjust during the day. This table does not tell you the temperature of a specific sunrise or evening.
Was every October similar? Seoul year by year
Even within this short sample, the years differed. The temperature column below averages each October’s daily mean temperatures. A precipitation day means a day with at least 0.1 mm, not necessarily a whole day of rain.
| Year | October mean, °C | Precipitation days |
|---|---|---|
| 2021 | 15.6 | 11 |
| 2022 | 14.6 | 5 |
| 2023 | 15.8 | 5 |
| 2024 | 16.7 | 6 |
| 2025 | 16.5 | 15 |
Sources: KMA daily observations, Seoul, KMA official precipitation-day statistics. Select Seoul and the relevant year and month in the official tools.
The number of precipitation days ranged from 5 to 15. That is a reason to carry rain protection, not a prediction of how many wet days your next trip will have. A five-year average can hide differences between individual Octobers.
How much rain did October bring in each city?
The figures below are the average October precipitation totals for 2021–2025, in millimetres. Each of the five monthly totals has equal weight. They are neither a daily rainfall rate nor a forecast for your travel dates.
| City | Average October precipitation, mm |
|---|---|
| Seoul | 94.5 |
| Incheon | 78.1 |
| Suwon | 89.0 |
| Chuncheon | 89.9 |
| Gangneung | 220.8 |
| Daejeon | 92.5 |
| Sejong | 93.6 |
| Cheongju | 89.9 |
| Busan | 73.3 |
| Daegu | 56.7 |
| Gwangju | 63.1 |
| Ulsan | 86.2 |
| Jeonju | 59.8 |
| Changwon | 70.0 |
| Pohang | 106.1 |
| Jeju | 63.8 |
Calculated from the KMA’s official monthly totals, checked for all 80 station-year combinations. Use the station selector and year controls in the official precipitation tables to inspect the source records.
Gangneung had the highest five-year average in this set, but the average hides large differences: its October total was 26.1 mm in 2023 and 486.2 mm in 2025. That does not establish what will happen in 2026, or mean that it rains continuously there. For a coastal itinerary, leave room to change an exposed outdoor plan when the actual forecast calls for it. KMA Gangneung precipitation records
What should you pack, including for rain?
Start with a light base layer, a long-sleeved option, a sweater or fleece and a jacket you can remove. Choose the warmth of the outer layer after checking the destination forecast. Add comfortable walking shoes and rain protection, such as a compact umbrella or a water-resistant outer layer appropriate to your plans.
Treat these as packing suggestions. No monthly temperature average can tell you whether your museum day, coastal walk or long outdoor evening will be dry. Keep an indoor alternative for a weather-sensitive outing, and check warnings before departing.
Where can you check the latest official forecast?
Open the KMA English short-term forecast, select the destination and check the forecast’s issue time and valid dates. Compare the temperature, precipitation and wind information for the hours you intend to be outside. Review any warnings linked from the official service, and check again shortly before departure.
For a multi-city trip, repeat that check for each stop. A five-year table helps you pack a range of clothing; the current local forecast helps you choose what to use that day.
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