Seoul Weather in September & October 2026: What to Wear, Packing List & Daily Temperature Swings

Ask any Seoul local when the absolute best time to visit South Korea is, and you will get the exact same answer: late September through October.

The sweltering summer monsoon humidity has completely vanished, skies turn a vibrant cobalt blue, and golden ginkgo and fiery maple leaves begin painting the royal palaces.

However, autumn in Seoul presents a unique packing challenge that catches 70% of foreign tourists off guard: the dramatic 10°C to 14°C daily temperature swing, known in Korean as Ilgyocha (일교차).

You can step out of your hotel in the morning at a crisp 11°C (52°F), work up a sweat at 23°C (73°F) while strolling Gyeongbokgung Palace at 2:00 PM, and find yourself shivering at 10°C (50°F) while eating ramen along the Han River at 9:00 PM.

Here is your complete 2026 guide to mastering Seoul’s autumn weather, what clothes to pack, and how to look stylish while staying comfortable.

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September vs October: Month-by-Month Breakdown

September Weather in Seoul (Summer-to-Autumn Transition)

• Average High: 25°C to 27°C (77°F to 81°F)
• Average Low: 16°C to 18°C (61°F to 64°F)
• Vibe: Early September still feels like pleasant late summer. By the third week of September (around the Chuseok Holiday), evening breezes turn distinctly crisp.
• What to Wear: Short-sleeve t-shirts or light blouses during the day, paired with a light denim jacket, oversized shirt, or lightweight cardigan for evenings.

October Weather in Seoul (Peak Autumn Perfection)

• Average High: 19°C to 21°C (66°F to 70°F)
• Average Low: 8°C to 11°C (46°F to 52°F)
• Vibe: The gold standard of travel weather. Sunny, dry, cool, with peak fall foliage spreading from Seoraksan down across Seoul’s Namsan and palace courtyards.
• What to Wear: Light trench coats, wool blazers, knit sweaters, trousers, and medium-weight outerwear. A thin thermal base layer (Uniqlo Heattech) is great for late night outdoor walking.

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The Essential Autumn Packing Checklist

🧳 What to Put in Your Suitcase

• Outerwear (The MVP): 1 classic trench coat, 1 denim or leather jacket, and 1 cozy fleece/cardigan.
• Tops: 3–4 basic cotton tees, 2 long-sleeve shirts, and 2 breathable knit sweaters.
• Bottoms: Comfortable straight-leg denim jeans, tailored slacks, or long midi skirts with tights.
• Footwear: 2 pairs of broken-in walking sneakers (Seoul’s subway transfers involve thousands of stairs!).
• Accessories: Compact umbrella (for occasional brief autumn rain showers), sunglasses, and a lightweight scarf.

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3 Local Styling Secrets for Seoul

1. The Subway Heat Trap

Seoul subway cars and boutique cafes run their indoor climate control aggressively. If you wear a heavy, non-removable sweater with nothing underneath, you will overheat the moment you step onto Subway Line 2. Always wear a breathable cotton t-shirt beneath your jacket or cardigan.

2. Renting Hanbok in Autumn

Early autumn is the peak season for Hanok photoshoots. Under modern Hanbok skirts, wear comfortable leggings and walking sneakers rather than restrictive dress shoes. Remember that wearing Hanbok grants you 100% Free Entry to All 5 Royal Palaces.

3. Han River Night Picnic Layering

One of Seoul’s greatest autumn traditions is renting a picnic mat and cooking foil-tray ramen at Yeouido or Banpo Hangang Park. Because wind blows off the river after dark, temperatures feel 3°C–4°C colder than downtown streets. Bring an extra jacket or hoodie for river nights.

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Frequently Asked Questions (FAQ)

Does it rain a lot in Seoul during autumn?

No. September and October are among Seoul’s driest months of the year, averaging only 4 to 6 rainy days per month. Rainfall is typically light and brief.

Do I need heavy winter boots or gloves?

No. Heavy winter snow boots and down-filled Arctic parkas are unnecessary in September and October. Standard sneakers, ankle boots, and regular socks are completely sufficient.

When do the autumn leaves peak in Seoul?

In downtown Seoul (Gyeongbokgung, Namsan Tower, Seoul Forest), peak autumn foliage occurs between October 22 and November 5. For mountain foliage forecasts across Korea, check our Korea Autumn Foliage Peak Leaf Map.

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Written by Yongwoo Chung, founder of Korea Made Easy. Meteorological benchmarks verified via Korea Meteorological Administration.