Monthly climate guide
Seoul weather in September
September in Seoul is typically warm, with average daytime highs around 25°C (76°F) and night-time lows near 17°C (62°F). The month usually brings about 108 mm of rain (wet) and is often cloudy. Daytime highs are 4°C cooler than August and 6°C warmer than October.
What stands out in September
- It cools down fast from here: October is about 6°C cooler.
- Check the hourly forecast before heading to Myeongdong — showers are likely.
- Just 70 km apart, but Seoul runs about 2°C warmer than Chuncheon this month.
- Seasonally, September counts as early autumn in Seoul.
Avg high
25°C
76°F
Avg low
17°C
62°F
Rainfall
108 mm
wet
Humidity
77%
relative
Sky
55%
cloud · often cloudy
Seoul weather by month
Show the monthly averages as a table
| Month | Avg high | Avg low | Rain | Humidity | Cloud cover |
|---|---|---|---|---|---|
| January | 1°C / 33°F | -7°C / 20°F | 17 mm | 76% | 56% |
| February | 3°C / 38°F | -5°C / 23°F | 33 mm | 73% | 53% |
| March | 9°C / 49°F | 0°C / 31°F | 30 mm | 74% | 48% |
| April | 16°C / 60°F | 5°C / 41°F | 74 mm | 73% | 53% |
| May | 22°C / 71°F | 11°C / 52°F | 76 mm | 73% | 54% |
| June | 26°C / 79°F | 17°C / 62°F | 106 mm | 74% | 63% |
| July | 28°C / 82°F | 21°C / 70°F | 345 mm | 83% | 75% |
| August | 29°C / 84°F | 22°C / 72°F | 243 mm | 82% | 65% |
| September | 25°C / 76°F | 17°C / 62°F | 108 mm | 77% | 55% |
| October | 19°C / 66°F | 10°C / 49°F | 62 mm | 73% | 43% |
| November | 11°C / 52°F | 3°C / 37°F | 59 mm | 75% | 55% |
| December | 3°C / 37°F | -5°C / 24°F | 26 mm | 76% | 55% |
What to pack for September
- T-shirts plus a light layer for the evening
- Comfortable trainers or sandals for long walks
- A compact umbrella or packable rain jacket
- Water-resistant shoes
Is September a good time to visit Seoul?
Our Seoul guide recommends: April to June or September to November, avoiding the summer monsoon and winter cold.
Wear a traditional hanbok (rentable near the palaces) for free entry to Gyeongbokgung — a popular and inexpensive way to visit.
Best time to visit Seoul →Other South Korea cities in September
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Seoul weather in September. WeatherCompare, 2026 (NASA POWER / ERA5, 2011–2020 monthly averages). https://weathercompare.eu/weather/south-korea/seoul/september
<a href="https://weathercompare.eu/weather/south-korea/seoul/september">Seoul weather in September</a> (WeatherCompare)
<iframe src="https://weathercompare.eu/embed/south-korea/seoul" width="300" height="160" style="border:0;border-radius:12px" loading="lazy" title="Seoul weather in September"></iframe> <p style="font-size:12px"><a href="https://weathercompare.eu/weather/south-korea/seoul/september">Seoul weather in September</a> – WeatherCompare</p>
Seoul in September: quick answers
Is September a good time to visit Seoul?
September is one of the wetter months in Seoul, with about 108 mm of rain. You can still go: pack a rain jacket and keep plans flexible.
How warm is Seoul in September?
Average highs are about 25°C (76°F) and average lows about 17°C (62°F), based on 10 years of daily data.
Does it rain a lot in Seoul in September?
Seoul typically gets around 108 mm of rain in September — wet.
When is the best time to visit Seoul?
April to June or September to November, avoiding the summer monsoon and winter cold.
Figures are long-term averages for the area around Seoul (NASA POWER / ERA5, 2011–2020), not a forecast for a specific year. For upcoming days, see the live multi-source forecast.