Temperatures by Month · Layering · Foliage Forecast · Dry Air · Packing List
🕐 Last verified: October 2026
Korean autumn changes fast. September still feels like summer, and by late November you need a winter coat. If you are used to Tokyo or Osaka weather, Seoul runs colder than you expect: about 3°C colder in October and about 5°C colder in November. This guide covers monthly temperatures, what to wear in early, mid and late month, the 2026 foliage forecast, dry air, and a packing list.
Quick answer — 3 things to know before you pack
Seoul is about 3°C colder than Tokyo in October and about 5°C colder in November. Seoul’s November average (7.5°C) is almost the same as Tokyo’s December average (7.7°C), so dress for November in Seoul as you would for December in Tokyo.
The daily swing is large, roughly 8–10°C in Seoul. Wear removable layers rather than one heavy coat, and add a light padded jacket from late October.
All figures here are 1991–2020 normals, and any given year can differ (October 2025 was the warmest October on record in Korea, 2.3°C above normal, per the KMA). Check the forecast a few days before you fly.
Temperatures Month by Month
Average temperature, with the typical daily low–high in brackets (°C). Seoul, Busan and Jeju are Korea Meteorological Administration (KMA) 1991–2020 normals; Tokyo and Osaka are Japan Meteorological Agency (JMA) normals for the same period.
City
Sep
Oct
Nov
Dec
Seoul
21.6 (17.7–26.2)
15.0 (10.6–20.2)
7.5 (3.5–11.9)
0.2 (−3.4–4.2)
Busan
22.6 (19.8–26.4)
17.9 (14.5–22.5)
11.9 (8.3–16.6)
5.8 (2.0–10.4)
Jeju City
23.3 (20.9–26.1)
18.6 (15.7–21.6)
13.3 (10.4–16.4)
8.3 (5.6–11.0)
Tokyo
23.3 (20.3–27.5)
18.0 (14.8–22.0)
12.5 (8.8–16.7)
7.7 (3.8–12.0)
Osaka
25.2 (21.9–29.5)
19.5 (16.0–23.7)
13.8 (10.2–17.8)
8.7 (5.3–12.3)
Seoul in November ≈ Tokyo in December. Seoul’s November average is 7.5°C against Tokyo’s 12.5°C, a gap of 5.0°C. October is 15.0°C against 18.0°C, a gap of 3.0°C. The typical November morning low is 3.5°C in Seoul versus 8.8°C in Tokyo. Packing from the average alone is the classic mistake: 7.5°C sounds mild until you are outside in the morning.
Busan is warmer than Seoul, by 2.9°C in October and 4.4°C in November. Jeju’s November low (10.4°C) is about the same as Osaka’s (10.2°C).
Big Daily Swings, Not Much Rain
The gap between the daytime high and the morning low (°C, 1991–2020 normals).
City
Oct
Nov
Seoul
9.6
8.4
Busan
8.0
8.3
Jeju City
5.9
6.0
Tokyo
7.2
7.9
Single years can stray far from these normals: the KMA reports that October 2025 was the warmest October on record nationwide (2.3°C above normal), with temperatures only falling back to normal in the last ten days of the month. Seoul is also far drier than Tokyo at this time of year: about 52 mm in October and 51 mm in November, against 235 mm and 96 mm in Tokyo. September is the wet month in Seoul (141.5 mm), so a compact umbrella still earns its place in early autumn.
What to Wear, Early, Mid and Late Month
A rough guide built from the monthly normals above and traveler reports. Actual days vary.
SEP Short sleeves, plus a thin layer for evenings
Seoul averages 21.6°C in September, with highs around 26.2°C and lows around 17.7°C. Daytime is still summer clothing. Keep a thin cardigan or long-sleeve shirt for the evening, and an umbrella.
EARLY OCT Still warm in the afternoon
October highs average 20.2°C, and early October afternoons can still feel like short-sleeve weather. Mornings are cooler (average low 10.6°C), so still bring a long-sleeve layer.
MID OCT Long sleeves plus a light jacket
With a 15.0°C average and a swing of nearly 10°C, a long-sleeve top with a cardigan, windbreaker or light jacket you can take off works well.
LATE OCT Coat or light padding time
One Japanese travel site notes that Seoul gets cold about 3–4 weeks earlier than Tokyo, and another suggests a light, long trench coat for late October. One Korean fashion platform (29CM) reported that light-padding sales from October 1 to November 13, 2025 were up 120% on the year before.
EARLY NOV Wool coat or light padding, knit, thermal underlayer
The November average is 7.5°C with a typical morning low of 3.5°C. The first ice in Seoul normally forms in early November (around November 3, worked out from KMA comparisons in news reports). Japanese travel writers also suggest Heattech-type thermal innerwear.
MID NOV Same setup, add a scarf
Indoors is warm (heating, ondol) and outdoors is cold, so choose an outer layer that is easy to take off and carry.
LATE NOV Dress for winter
Late-November mornings and evenings can get close to freezing. The first snow in Seoul normally falls around November 20 (estimated from news reports, not an official figure), so snow is possible. Pack a padded coat, gloves and hand warmers.
EARLY DEC Full winter gear
Seoul’s December average is 0.2°C, with a typical high of 4.2°C and low of −3.4°C.
Light padding is a multi-season item. Korean fashion media describe it as an outer layer in autumn and an inner layer in winter, which is why it is worth buying or packing even if you will be here only until November.
2026 Fall Foliage: Forecast Peak Dates
From the Korea Forest Service forecast reported by Maeil Shinmun on October 16, 2026. The first autumn color of the year was seen on September 14 at Jeombongsan.
Place
Forecast peak (2026)
Nationwide (broadleaf: maples and oaks)
October 31 (0.8 days later than the 5-year average)
Seoraksan (maples)
October 20 (already past as of this guide)
Naejangsan
October 26 (oaks) / November 4 (maples)
Jirisan
October 27
Songnisan, Palgongsan
October 28
Yumyeongsan Natural Recreation Forest (Gyeonggi)
October 31
Hallasan, 1100 Road (Jeju)
November 6
“Peak” is defined differently. The Forest Service counts the day half or more of its observed trees have colored; the KMA counts the day 80% of a mountain has colored from the top down. Dates also differ by two to three weeks from mountain to mountain, so match the date to the mountain, not to “Korea”.
No peak date was published for central Seoul (palaces, Namsan). Yumyeongsan Natural Recreation Forest in Gyeonggi (October 31) is the nearest guide. Some trails need reservations: Seoraksan’s Heulrimgol section takes advance bookings until November 30, and Naejangsan’s Gatbawi section runs October 19 to November 17 with 790 people a day. For an easy outing from the city, see our Suwon & Gyeonggi day trip guide.
Dry Air, Fine Dust and Handy Items
The things that surprise visitors after the temperature.
Indoor air is dry
Ondol (underfloor heating) tends to dry the air. A Japanese-language Seoul housing guide says waking up with a dry throat is common. Bring lip balm and moisturizer.
November mornings are colder than the average
The November average of 7.5°C hides cold mornings, with a typical low of 3.5°C in Seoul. Do not cut your layers to match the average.
Contact lens wearers
Travelers on Reddit ask whether contact lenses are comfortable in Korea’s dry autumn air. Bring lens drops or a pair of glasses as a backup.
Hand warmers are cheap
Daiso sells a 2-pack of pocket hand warmers for ₩1,000. The product listing gives a maximum of 75°C, an average of 63°C and about 14 hours of heat (Daiso Mall).
Fine dust: autumn comes before the high season
The high-concentration season is December to March, the period covered by Seoul’s seasonal management program, so autumn comes before it. Yellow dust is not only a spring issue: the KMA says it can occur in autumn and winter too, but not in summer. This guide does not give autumn PM2.5 figures, so check an air-quality app on the day.
Packing Checklist
What to put in the bag for September to November.
Item
Why
Thin long-sleeve tops, cardigan
Daily swing of 8–10°C; indoors is warm, outdoors is cold
Windbreaker or light jacket
October, when afternoons are mild and mornings are not
Light padded jacket or wool coat
From late October; the main coat for November
Thermal innerwear
November mornings average 3.5°C in Seoul
Scarf and gloves
Late November and early December
Hand warmers
₩1,000 for 2 at Daiso
Lip balm, moisturizer, lens drops
Dry indoor air from heating
Compact umbrella
September is the rainy month (141.5 mm in Seoul)
Frequently Asked Questions
Based on 1991–2020 normals, Seoul’s October average is 15.0°C against 18.0°C in Tokyo (3.0°C colder), and November is 7.5°C against 12.5°C (5.0°C colder). Seoul’s November average is nearly the same as Tokyo’s December average of 7.7°C, so November in Seoul calls for December clothing from Tokyo.
Early October afternoons can still be warm enough for short sleeves, but the average morning low is 10.6°C. Mid October suits long sleeves with a removable cardigan or light jacket. From late October, bring a coat or a light padded jacket. The daily swing averages 9.6°C, so layers matter more than one thick item.
Yes. November averages 7.5°C in Seoul with a typical morning low of 3.5°C, and late-November mornings and evenings can get close to freezing. The first snow normally falls around November 20 (an estimate from news reports). A padded coat, gloves, a scarf and hand warmers are sensible.
The Korea Forest Service forecast is October 31 nationwide and for Yumyeongsan Natural Recreation Forest near Seoul. Jirisan is October 27, Songnisan and Palgongsan October 28, Naejangsan October 26 (oaks) and November 4 (maples), and Hallasan’s 1100 Road November 6. Seoraksan’s October 20 peak has already passed. Peak dates differ by two to three weeks from mountain to mountain.
Yes. Busan averages 2.9°C warmer than Seoul in October (17.9°C) and 4.4°C warmer in November (11.9°C). Jeju City averages 18.6°C in October and 13.3°C in November, and its November low of 10.4°C is close to Osaka’s 10.2°C. Even so, a jacket is still useful in the mornings and evenings.
Indoor air tends to be dry because of ondol heating. Fine dust is mainly a December to March issue in Seoul, and yellow dust can occur in autumn and winter as well as spring, but not in summer. Check an air-quality app on the day you travel.
The Bottom Line
Plan for layers: the daily swing is 8–10°C, Seoul in November is as cold as Tokyo in December, and a light padded jacket becomes useful from late October. The figures here are 1991–2020 normals, so check the forecast a few days before you fly. For your next steps, browse more Must-Know Tips on innerkorea.com.