Seoul has four sharply defined seasons: cold, dry winters, hot and very wet summers, and short, pleasant springs and autumns. Its clock runs on Korea Standard Time, nine hours ahead of UTC, with no daylight saving.
Climate overview
Seoul sits in a basin on the Han River in northwest South Korea, surrounded by mountains. It has a monsoon-influenced humid continental climate (Köppen Dwa). In winter, cold, dry winds blow from Siberia; in summer, warm, moist air flows in from the Pacific.
Average highs range from 2°C in January to 30°C in August. Annual rainfall is about 1,418 mm, and well over half of it falls from June to August, during and after the rainy season called jangma. July is the wettest month, averaging about 414 mm, while the winter months receive only 17–28 mm. Seoul gets about 2,143 hours of sunshine a year, with the least in the rainy summer.
Seoul through the seasons
Winter (December to February)
Winters are cold and dry, with January highs of 2°C and lows of −6°C. Cold waves from Siberia can bring much harsher spells. Snowfalls are usually light, and skies are often clear and blue. The Han River sometimes freezes in very cold winters.
Spring (March to May)
Spring warms quickly, from 11°C in March to 24°C in May. Cherry blossoms usually bloom in early April. Spring is also the season of yellow dust (hwangsa) blown from the deserts of China and Mongolia, and of high fine-dust levels. May is one of the sunniest months, with about 223 hours of sun.
Summer (June to August)
Summers are hot and humid, with highs of 28–30°C and warm nights around 23°C. The jangma, usually from late June to late July, brings intense rainfall, and July is the dullest month, with only 124 hours of sunshine. Hot, sticky weather follows in August, which is still very wet at about 348 mm, and typhoons occasionally reach the Korean Peninsula.
Autumn (September to November)
Autumn is the most comfortable season, with clear skies and drier air. Temperatures fall from 26°C in September to 12°C in November, and October is famous for colourful leaves on the mountains around the city.
What makes Seoul's weather distinctive
Seoul has one of the largest seasonal temperature ranges of any major city: a January cold snap and an August heatwave feel like different climates. The jangma and the weeks after it can bring extremely heavy rainfall in short periods; in August 2022, record-breaking downpours flooded parts of southern Seoul, including the Gangnam area.
Air quality is a daily topic. Fine dust (misemeonji) levels are reported in forecasts, and on high-dust days many people wear masks and limit outdoor activity, especially in spring and winter. Our Weather page shows live conditions and the forecast.
The mountains matter too. Bukhansan and the other peaks that ring the city are a few degrees cooler than the streets below, and they catch the autumn colours first.
Best time to visit Seoul
April to June and September to October are the best times to visit Seoul. Spring brings blossoms and mild weather, with highs of 18–24°C in April and May, while autumn offers blue skies, comfortable temperatures and spectacular foliage.
Winter is cold but clear and good for skiing trips nearby. July and August are the least comfortable months, with heavy rain, heat and humidity.
If you do travel in summer, carry an umbrella every day, plan indoor options such as museums and covered markets for wet afternoons, and check the forecast for typhoon warnings in August and September.
What to pack
- A heavy coat, gloves, hat and scarf for winter
- An umbrella and quick-drying clothing for the rainy season
- Layers for spring and autumn
- A mask (KF94) for fine-dust days
- Comfortable shoes for hilly neighbourhoods and mountain trails
Time in Seoul
Seoul uses the Asia/Seoul time zone, Korea Standard Time (KST), which is UTC+9 all year; South Korea does not use daylight saving time. It last did so in 1987 and 1988, around the Seoul Olympics. Right now Seoul is 9 hours ahead of London and 2 hours behind Sydney. Seoul keeps the same clock time as Tokyo, which makes scheduling across the two capitals simple.
| With | Difference | Time in Seoul | Their time |
|---|---|---|---|
| London | −9 h | No overlap | – |
| New York | −14 h | No overlap | – |
| Dubai | −5 h | 14:00–18:00 | 09:00–13:00 |
| Tokyo | same time | 09:00–18:00 | 09:00–18:00 |
| Sydney | +2 h | 09:00–16:00 | 11:00–18:00 |
| Date | Sunrise | Sunset | Day length |
|---|---|---|---|
| 20 March | 06:35 | 18:43 | 12 h 7 min |
| 21 June | 05:10 | 19:56 | 14 h 45 min |
| 22 September | 06:19 | 18:30 | 12 h 10 min |
| 21 December | 07:42 | 17:17 | 9 h 34 min |
Frequently asked questions
When is the rainy season in Seoul?
The jangma usually runs from late June to late July, though heavy rain is also common in August.
How cold is Seoul in winter?
January averages about 2°C by day and −6°C at night, and cold waves can bring much lower temperatures.
When is the best time to see autumn leaves in Seoul?
Mid to late October, when the mountains around the city turn red and gold.
When do the cherry blossoms bloom in Seoul?
Usually in early April, though the exact dates vary with the warmth of the spring.
Is Seoul humid in summer?
Yes. From late June to August the air is hot and sticky, with frequent heavy rain, while winter air is cold and dry.
Does South Korea use daylight saving time?
No. Seoul stays on UTC+9 all year; the last time Korea changed its clocks was in 1988.