Seoul weather in December
December in Seoul: cold, dry — a fair time to visit.
Updated September 2026 · climate normals from ERA5 reanalysis
#10 of 12 months in Seoul · #1134 of 1413 destinations to visit in December · comfort 52/100 (tier D)
- Days
- 4°C
- Nights
- -4°C
- Wet days
- 5
- Sun
- 7.3 h
- Humidity
- 63%
- Daylight
- 10 h

What December is like in Seoul
Cold and dry with hard winds. Markets and underground arcades are the warm places, and the first snow usually falls.
snowlow season
confidence: high
Traveller notes on Seoul in December
Other months in Seoul
Regulars describe typhoon risk this month as genuinely random rather than a serious, consistent threat - even when a significant one is forecast, the actual disruption typically runs two to three days rather than derailing a whole trip, and August is named as the more typhoon-prone month by comparison. Our row backs a still-warm, humid read, 27.5C reading as a hot 30C at 79 percent humidity, over 18.7C nights, with a real 148.2mm of rain across 9.1 days. Regulars call the back half of the month into early October one of the best overall windows of the year, pleasant and not too hot. Summer clothes plus a light jacket for cooler evenings or rural areas is the standard advice. The sea sits at 25.8C. The record: 8.2 hours of sun, a 12.6 kph wind and AQI 73.
August is the hottest month here and regulars measure it in minutes: ten outside and you are sweating. Our row gives 31.2C reading as 36C at 83 percent humidity over 24.2C nights. The jangma has usually finished by the end of July, so this is not everyday rain - but it is the wettest month we hold for the city at 243.6mm across 14.5 days, which means it arrives hard when it comes. Typhoon season overlaps and nobody can schedule one; the board's wry consolation is that a typhoon at least breaks the heat for a day or two. Anything outdoors belongs to early morning or after dark. The record: 8.6 hours of sun, a 28.4C sea and AQI 93.
June here is two months in one and regulars date the join: the first half is hot by day, cooler at night and mostly dry, and around the fourth week the jangma arrives and turns it wet and sticky. Our 115.7mm across 8.9 days is that shape, not an evenly damp month - most of it falls in the last week or so. Before then the numbers are kind: 28.5C reading as 30C at 75 percent humidity, nights at 19.4C, and 14.7 hours of daylight. Anyone with a choice inside the month should take the first fortnight; anyone arriving late should expect heavy showers rather than all-day rain. The record: 10 hours of sun, a 22.6C sea and AQI 86.
May in Seoul is the month that changes under you: regulars say the first week still wants a light jacket or a cardigan, and by the last week you rarely need more than a t-shirt. Their figures - highs of 20 to 25C, lows of 13 to 16C - bracket our row's 24.2C and 13.7C. The standing advice is layers, because the drop in the early morning and again in the evening is the part visitors get wrong, and the jacket they recommend is one that will also shed rain. That last point is the one our row sharpens: 105.2mm falls in May across 8.1 days, more than the spring reputation suggests, and it arrives well before the proper summer monsoon. The record: humidity 71 percent, 10 hours of sun and AQI 86.
Year-round notes are on Seoul's overview. Add your own note from Seoul's card on the map.
Seoul climate normals — December
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Seoul in December
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
Quietthe editor's quiet month, Winter break (gyeoul banghak) in South Korea, school holidays in 4 of the markets that fill it
Peak crowdsBusyShoulder seasonQuiet
Best months for Seoul's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Toughest weatherSeoul's best weather comes in April, May and October — separate windows, not one continuous season.
Best weatherFair weatherToughest weather
What's on in Seoul in December
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Festival
Gimjang, kimchi-making
15 Nov – 10 Dec · usuallyFood & drink festivalThe communal cabbage-salting season, on UNESCO's heritage list, fills courtyards and apartment car parks for a few weeks before the ground freezes. Source ↗
- Season
Ski season an hour out
10 Dec – 5 Mar · usuallyThe Gangwon resorts run on cold, dry, machine-heavy snow from December, and the day trips from Seoul are the reason people ski here at all. Source ↗
Where is Seoul?
Seoul in December — FAQ
- Is December a good time to visit Seoul?
- December in Seoul: cold, dry — a fair time to visit. It ranks #10 of 12 months for Seoul on SeasonMap's comfort score (52/100).
- What is the weather like in Seoul in December?
- In December, Seoul averages a daily high of 4.4°C and a low of -4.3°C, with about 26.4 mm of rain over roughly 5 rainy days.
- What is the air quality in Seoul in December?
- Seoul has a mean US Air Quality Index of about 77 in December.
- Does it snow in Seoul in December?
- Seoul sees roughly 5.5 cm of snowfall in December.