WanderWhen

Seoul weather in September

September is one of the best months to visit Seoul. Expect highs around 26°C, lows near 18°C, and about 11 days with rain.

8.8 · Excellenttravel score for September
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Avg high
26°C
Avg low
18°C
Rainfall
190 mm
Rain days
11
Sunshine
8.2 h/day
Daylight
12.2 h

What to pack for Seoul in September

  • t-shirts and light layers
  • a light jacket for evenings
  • a compact umbrella or rain shell — rain is frequent

Humidity averages 79%; max daily wind around 15 km/h.

How September compares

January: 1.8/10 JFebruary: 3.3/10 FMarch: 6.6/10 MApril: 9.8/10 AMay: 9.6/10 MJune: 8.9/10 JJuly: 5.2/10 JAugust: 5.1/10 ASeptember: 8.8/10 SOctober: 9.8/10 ONovember: 6.2/10 NDecember: 2.0/10 D

Best months in Seoul: April–May & October. See the full best time to visit Seoul guide.

Seoul in September: the details

In September, Seoul sees average daytime highs of 26°C (78°F) and overnight lows of 18°C (64°F). Rainfall totals roughly 190 mm across 11 rainy days, and the sun shines about 8.2 hours per day with 12.2 hours of daylight mid-month. Relative humidity averages 79%.

These figures are climate normals computed from the ERA5 weather reanalysis (2019–2024) for Seoul, South Korea (37.57, 126.98) — see our methodology. Actual conditions vary year to year.

Where should you go next month?

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