Seoul weather
in September
“Mild and bright — an underrated time to visit.”
Roughly 9 rainy days across the month, on average.
In september, Seoul settles into its kind, mild rhythm. The city keeps a different pulse than in summer or midwinter, and travellers who arrive with the right expectations are rewarded.
Days average around 25°C (78°F), cooling to 17°C after sunset. Expect meaningful rain — some 9 wet days across the month. Pack accordingly and let the weather choose your afternoons. Long days of sunshine reward early starts.
These figures are climatological averages, drawn from a decade of daily records via the Open-Meteo Archive — not a forecast. But they are honest, and they are the sort of thing a good travel guide ought to tell you before you book the flight.
What to pack for Seoul in September
- •A light layer for cool mornings and evenings
- •A compact travel umbrella — one you'll actually carry
- •Reef-safe sunscreen and polarised sunglasses
- •Comfortable, broken-in walking shoes
- •A small daypack that won't look like a tourist beacon
What to pack for Seoul in September
- →Breathable travel pantsAmazon · shop this
- →Packable rain jacketAmazon · shop this
- →Compact travel umbrellaAmazon · shop this
- →Waterproof dry bagAmazon · shop this
- →Reef-safe sunscreen SPF 50Amazon · shop this
- →Polarized sunglassesAmazon · shop this
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Where to stay in Seoul
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Compare hotels on Booking.com→Other places with a similar climate right now
Seoul in September — FAQ
Q01Is September a good time to visit Seoul?
Is September a good time to visit Seoul?
It is a fair time to visit — expect variable conditions and plan flexibility. In September, Seoul averages a high of 25°C (78°F) and a low of 17°C (63°F), with 127mm of rainfall across roughly 9 rainy days.
Q02What is the average temperature in Seoul in September?
What is the average temperature in Seoul in September?
The average high temperature in Seoul during September is 25°C (78°F), with an average low of 17°C (63°F). These figures are averaged from ten years of daily records (2015–2024, Open-Meteo Archive).
Q03How many rainy days does Seoul have in September?
How many rainy days does Seoul have in September?
Seoul averages approximately 9 rainy days in September, with a total monthly rainfall of about 127mm. This is based on daily precipitation records where days with 1mm or more of rain are counted as rainy days.
Q04What should I pack for Seoul in September?
What should I pack for Seoul in September?
For Seoul in September, pack layered clothing for changing temperatures, a compact umbrella or waterproof jacket, sunscreen and sunglasses, comfortable walking shoes. These recommendations are based on the ten-year weather averages for this specific month.
Q05How crowded is Seoul in September?
How crowded is Seoul in September?
Tourist crowds in Seoul during September are typically moderate — shoulder season, a sweet spot between crowds and weather. Consider this when planning accommodation — prices track crowd levels closely.