Seoul Weather in December
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Asia › 🇰🇷 South Korea › Seoul
Updated: March 2026
Is December a Good Time to Visit Seoul?
December is a fair time to visit Seoul (4/10). With 7 daily sunshine hours and only 5 rain days, this month delivers genuinely reliable outdoor conditions, ranking it 12th sunniest of the year in Seoul. December suits travellers visiting for indoor culture, food, and architecture rather than outdoor activities. Pack accordingly for 5 potential rain days. January offers a similar profile at lower hotel rates if dates are flexible. The 3°C highs require proper cold-weather clothing; many visitors underestimate how far the wind chill drops the perceived temperature, particularly near water or at elevated viewpoints. Planning tips: most accommodation categories have availability, and last-minute deals are common. The quieter streets and shorter queues can make this a genuinely enjoyable time to visit for the right type of traveller. Budget-conscious visitors will find the best value of the year in this period.
December weather in Seoul is defined by a daily temperature swing from -5°C at night to 3°C during the afternoon. Humidity averages 65%, and you can count on around 7 sunshine hours each day. That combination makes December warm and lush, though dressing in breathable fabrics keeps things manageable.
3°C
Avg High
-5°C
Avg Low
5 days
Rain Days
7h
Sunshine
65%
Humidity
Temperature in Seoul in December
The 8°C day-night temperature range is typical for continental climates: a light jacket in the morning that you shed by midday and need again after sunset. Humidity averages 65%, which is comfortable for most visitors. On warmer days, lighter fabrics help with the mild stickiness in the afternoon. The UV index of 1 is low, meaning sun exposure is minimal concern and sunscreen is largely optional. Wind averages 15 km/h, light enough to be refreshing on warm days but noticeable in open coastal areas or elevated viewpoints. In Fahrenheit: 37°F average high, 23°F overnight low. Data sourced from Open-Meteo ERA5 climate reanalysis (1991–2020 normals).
Temperature in December
Monthly Precipitation (mm)
What to Wear in Seoul in December
Packing for Seoul in December means dressing for 3°C days and -5°C evenings. Layering is key: a thermal base, mid-layer fleece, and a windproof outer jacket for 3°C highs that feel colder in the wind. Evening temperatures settle at -5°C, a modest 8°C drop that a light cardigan or denim jacket covers. Comfortable walking trainers are the versatile choice for both outdoor sightseeing and indoor venues.
Local tip: Temple and religious site visits require covered shoulders and knees in most of Seoul's heritage areas. A lightweight scarf or sarong weighs almost nothing and solves the problem instantly.
Events in Seoul in December
December has no major festivals or public holidays in Seoul, which is one of its practical advantages for independent travellers. Attractions run at lower capacity than during peak event periods, queues are shorter, and accommodation is easier to find without needing to book many months in advance. Local restaurants, markets, and transport operate at a relaxed pace, making this an ideal time for visitors who prefer a more authentic, unhurried experience of everyday city life rather than large crowds drawn in by a single major headline event.
What to Pack for Seoul in December
Based on 3°C average highs and 5 rainy days
- Heavy winter coat (rated below -5°C)
- Thermal underlayers in merino wool or moisture-wicking synthetic
- Insulated, waterproof boots
- Wool hat, thick gloves, and a windproof scarf
- Comfortable walking shoes (a second pair lets the first air out overnight)
- Universal travel adapter
- Small day pack for city exploration
- Reusable water bottle
Best Activities in Seoul in December
- Vigorous walking tour of the UNESCO heritage districtMidday (12-2pm)The 3°C peak temperature provides ideal conditions for brisk sightseeing walks
- Cycling the riverside or park circuitAfternoon (1-4pm)Cool dry air makes long cycling sessions comfortable without overheating
- Explore hilltop viewpoints and fortressesMorning for clear viewsCold-weather atmospheric clarity gives the longest sightlines of the year
- Open-air Christmas or seasonal marketsAfternoon into eveningCool temperatures make festive outdoor markets genuinely atmospheric
- Afternoon in a world-class museum or galleryAfternoon (2-5pm)Pairs well with outdoor morning activities and provides a mid-day rest from sightseeing
- Coffee-house or traditional cafe culture experienceMid-morning or post-lunchA cultural ritual in this region that rewards slow appreciation regardless of weather
- Evening live music, theatre, or opera performanceEvening shows typically at 7-9pmConsistent evening temperatures make getting to and from evening venues comfortable
- Visit the main botanical garden or city park at seasonal peakYear-round; best light in morningDecember brings distinct seasonal changes to public green spaces worth exploring
- Warm up with traditional hot dishes: local stew, fondue, or braised specialities at a neighbourhood restaurantLunch (12-2pm) or dinner (7-9pm)Cold-weather cuisine is a genuine cultural experience and the best local restaurants serve their heartiest dishes in cooler months
Why is Seoul cool in December?
December in Seoul reflects a mid-latitude climate pattern, with temperatures averaging 3°C by day and -5°C overnight. The city sits at 38 degrees north latitude, where the balance between solar radiation and heat loss drives conditions that are neither extreme nor static. Cold conditions reflect the dominance of polar or continental air masses, which bring dry, stable weather with low humidity. Day-to-night temperature variation of 8°C is moderate and manageable with a single mid-layer. Climate data: Open-Meteo ERA5 (1991–2020).
Sunshine Hours
The average number of hours per day with direct sunlight. Calculated from satellite measurements. Days with more than 7 hours of sunshine are ideal for outdoor activities. Under 3 hours means overcast conditions dominate.
UV Index
A scale from 0-11+ measuring ultraviolet radiation intensity. UV 0-2: Minimal risk. UV 3-5: Moderate -- wear sunscreen. UV 6-7: High -- hat and SPF 30+ essential. UV 8-10: Very High -- limit midday exposure. UV 11+: Extreme -- seek shade between 10am-4pm.
Rain Days
A rain day is counted when precipitation exceeds 0.1mm. This threshold captures even light drizzle. Unlike total rainfall in mm, rain days tells you how often you might need an umbrella, which is useful for planning outdoor activities.
Humidity
Relative humidity as a percentage. Below 40%: Dry -- skin and throat may feel parched. 40-60%: Comfortable -- ideal for most people. 60-80%: Sticky -- light, breathable fabrics recommended. Above 80%: Muggy -- heat feels more intense; quick-dry clothing is essential.
Frequently Asked Questions: Seoul in December
December ranks 12th sunniest of the year in Seoul, with an average 7 daily sunshine hours. The driest months are January, February, and October. August is the hottest month (29°C avg high); January is the coolest (1°C). From here, temperatures fall 2°C into January. Compared to last month (November: 11°C high, 7 rain days), December is cooler and drier. December is one of the least sunny months, but that often means lower prices and fewer fellow tourists.
Year-Round Climate
Plan Your Trip to Seoul
Nearby Destinations with Similar Weather
These cities are within 500 km and experience broadly comparable weather conditions during the same calendar month, making them practical standalone alternatives or worthwhile additions to a longer regional itinerary.
Data Sources for Seoul
Climate normals represent 30-year averages (1991-2020). Individual years may vary.