01Weather
Seoul weather in September
Afternoons in September average 27.1 °C (81 °F) and nights cool to 19.3 °C (67 °F). Compared with August it is 3.9 °C cooler; October is 7.0 °C cooler again.
What the averages hide
| In a typical September | Value | What it means |
|---|---|---|
| Warm afternoons (90th percentile) | 31 °C / 87 °F | one day in ten is at least this warm |
| Cool afternoons (10th percentile) | 23 °C / 74 °F | one day in ten stays below this |
| Cold nights (10th percentile) | 16 °C / 60 °F | one night in ten is colder than this |
| Days above 30 °C (86 °F) | 4.2 | per month, average 2016–2025 |
| Nights at or below 0 °C (32 °F) | 0.0 | frost mornings per month |
| Hottest / coldest September day 2016–2025 | 34.5 °C / 10.8 °C | extremes in the ten-year record |
02Daylight
Sunrise, sunset and the length of the day
| Date | Sunrise | Sunset | Daylight |
|---|---|---|---|
| 1 September | 06:02 | 19:01 | 13.0 h |
| 15 September | 06:14 | 18:40 | 12.4 h |
| 30 September | 06:26 | 18:17 | 11.8 h |
Daylight shrinks by about 72 minutes over the month. Times are local (Asia/Seoul).
03Crowds
How busy Seoul is in September
busy The main sights are busy in September. What drives it:
- Chuseok harvest festival in September or October
- pleasant weather returns
04Public holidays
Public holidays in September 2027
| Date | Holiday |
|---|---|
| 14 Sep 2027 | Chuseok |
| 15 Sep 2027 | Chuseok |
| 16 Sep 2027 | Chuseok |
On public holidays many shops close and museums run on Sunday hours; check opening times for the day before and after as well.
05Events
What's on in Seoul in September
Every year in September
| Event | When | Type |
|---|---|---|
| Chuseok | September or early October, three-day harvest holiday | holiday |
07Packing
What to pack for Seoul in September
- light, breathable clothing
- sun hat and sunscreen
- refillable water bottle
- a compact umbrella for occasional showers
- something for heat: 4 days a month pass 30 °C on average
08Editor's notes
What the numbers don't tell you
September brings relief, with humidity dropping and clear days returning in the second half, afternoons around 26 °C. Chuseok, the harvest holiday, often falls this month and closes much of the city for three days while the palaces fill with people in hanbok and the trains sell out. It is the start of the best season. Rain falls on about eight days, with typhoon risk in the first half.
The Seoul Fashion Week and the Seoul Design Festival fall in autumn. The Han River parks and the Cheonggyecheon stream are busy in the evenings. Hotel rates rise toward October. The Seoul International Fireworks Festival at Yeouido falls on a Saturday in late September or October and draws a million people. For the finest month, see October.
09Compare
Seoul month by month
| Month | High | Low | Rain days | Sun h | Crowds | Verdict |
|---|---|---|---|---|---|---|
| January | 3 °C | -5 °C | – | – | quiet | Good |
| February | 6 °C | -3 °C | – | – | quiet | Good |
| March | 13 °C | 3 °C | – | – | moderate | Good |
| April | 20 °C | 9 °C | – | – | very busy | Good |
| May | 24 °C | 14 °C | – | – | busy | Excellent |
| June | 28 °C | 20 °C | 17 | – | moderate | Good |
| July | 31 °C | 24 °C | 20 | – | quiet | Mixed |
| August | 31 °C | 25 °C | 19 | – | moderate | Mixed |
| September | 27 °C | 19 °C | – | – | busy | Excellent |
| October | 20 °C | 11 °C | – | – | very busy | Good |
| November | 13 °C | 4 °C | – | – | moderate | Good |
| December | 4 °C | -4 °C | 11 | – | moderate | Mixed |
Not sure about September? See the best time to visit Seoul.
10Elsewhere
September in nearby cities
| City | High | Rain days |
|---|---|---|
| Kyoto in September | 30 °C | 10 |
| Shanghai in September | 30 °C | 12 |
| Beijing in September | 28 °C | 8 |
| Tokyo in September | 28 °C | 12 |
| Bangkok in September | 33 °C | 24 |
| Singapore in September | 32 °C | 11 |
11FAQ
Seoul in September: your questions
Is September a good time to visit Seoul?
September is one of the best months to visit Seoul. Daytime highs average 27 °C (81 °F), and hotel arrivals run above the yearly average, so the main sights are busy.
What is the weather like in Seoul in September?
Expect warm days around 27 °C (81 °F) and nights near 19 °C (67 °F). One September in ten brings afternoons above 31 °C, and one in ten stays below 23 °C.
Does it rain a lot in Seoul in September?
September in Seoul, by the 1991–2020 station normals.
What should I wear in Seoul in September?
Pack light, breathable clothing, sun hat and sunscreen, refillable water bottle.
Is Seoul crowded in September?
The main sights are busy in September. Main drivers: Chuseok harvest festival in September or October; pleasant weather returns.
What time does it get dark in Seoul in September?
Around the middle of September the sun sets at about 18:40 and rises at 06:14, giving 12.4 hours of daylight.