Seoul Weather in September
September in Seoul brings high temperatures around 27°C (81°F) during the day, dropping to 17°C (63°F) at night, with quite a bit of rainfall expected, averaging around 128 mm (5 in) for the month.
Rainfall in Seoul in September
Historically, September sees about 9 days of rain, with a monthly average of 128 mm (5 in). When showers do arrive, they tend to be on the heavier side. Worth being prepared even if rain days are not that numerous.
Temperature in Seoul in September
In September, Seoul sees high temperatures, with highs of 27°C (81°F). Nights drop to around 17°C (63°F). This kind of day-to-night contrast is typical for this time of year. At 17°C (63°F) overnight, it can feel quite a bit cooler after dark. Worth packing something warmer for evenings, but the cooler temperatures are ideal for sleeping.
Sunshine in Seoul in September
With about 182 hours of sunshine, the area enjoys a nice balance of sun and overcast, creating a pleasant environment.
Wind Speed in Seoul in September
Average wind conditions reach 2 m/s (4 knots) in September. This creates comfortable weather with light winds that gently move vegetation. Keep in mind this is an average. Daily conditions range from near-calm to more noticeable wind.Our weather planner can help you find worldwide destinations with pleasant weather during this period. May and October typically offer the best weather for Seoul.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit South Korea, check out our Seoul's climate page.
Seoul Temperature in September
Min Temperature
17°C (63°F)
Max Temperature
27°C (81°F)
Chance of Rain
29%
Precipitation
128 mm (5 in)
Rainy days
9 days
Humidity
67%
Windspeed
2 m/s (4 knots)
Sunshine
182 hours
Percentage Sunshine
48%
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Seoul typically drop from around 28°C (82°F) at the start of September to approximately 24°C (75°F) by the end. Nights are pleasant, with lows typically ranging from 13°C (55°F) to 20°C (68°F).
Average temperatures in September
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in September
Historical weather for Seoul in September
Browse day-by-day weather records for Seoul spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Seoul historical weather extremes in September
Based on 49 years of weather observations in Seoul between 1976 and 2025, these are the recorded extremes.
- On September 11, 2024, temperatures climbed to 35°C (95°F), marking the warmest September day on record.
- Seoul experienced its chilliest September day on September 26, 1987, reaching only 16°C (61°F).
- The lowest overnight temperature recorded in September was 5°C (41°F) (September 27, 1987).
Best Places in South Korea in September
Find out more about the weather in South Korea and which places have the best travel conditions in this month. See all of South Korea in September →
perfect weather
pleasant
tolerable
unpleasant
poor
What to Wear in Seoul in September
Warm weather calls for comfortable, breathable clothing in September. Cotton t-shirts, shorts, light dresses, and sandals are perfect. You might still want a light layer for evenings or air-conditioned places (for example buses). High rain levels are expected, so pack waterproof gear and an umbrella or poncho. Sunglasses could come in handy during the sunnier parts of your trip.What To Do in Seoul in September
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit South Korea, check out our Seoul's climate page.
Temperature Rainfall Sunshine Humidity Wind Speed
See the full Seoul climate overview or explore weather in South Korea.
