September weather forecast and climate
Seoul, South Korea

The Dongdaemun Gate in Seoul city, South Korea
The Dongdaemun Gate in Seoul city, South Korea
The first month of the autumn, September, is still a warm month in Seoul, South Korea, with average temperature varying between 17.2°C (63°F) and 25.8°C (78.4°F).

Temperature

In September, the average high-temperature slightly decreases, from 29.6°C (85.3°F) in August, to a still moderately hot 25.8°C (78.4°F). The average low-temperature, in Seoul, is 17.2°C (63°F).

Humidity

The average relative humidity in Seoul, South Korea, is 69.2%.

Rainfall

In Seoul, South Korea, during 9.1 rainfall days, 169.3mm (6.67") of precipitation is typically accumulated. Throughout the year, in Seoul, there are 108.8 rainfall days, and 1450.6mm (57.11") of precipitation is accumulated.

Daylight

In September, the average length of the day in Seoul is 12.4h.

Sunshine

The average sunshine in September is 5.9h.

UV index

The average daily maximum UV index in September is 7. A UV Index reading of 6 to 7 represents a high health risk from the exposure to the Sun's UV radiation for ordinary individuals.
Note: In September, the average maximum UV index of 7 translate into the following recommendations:
Take precautions and utilize sun safety practices. Protection against the skin and eye damage is required. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun.

What is the temperature in September in Seoul?

In Seoul, in September, the average high-temperature is 25.8°C (78.4°F), and the average low-temperature is 17.2°C (63°F).

What is the average humidity in September in Seoul?

The average relative humidity in September is 69.2%.

How much does it rain in Seoul in September?

In Seoul, South Korea, in September, it is raining for 9.1 days, with typically 169.3mm (6.67") of accumulated precipitation.

How many hours of daylight does Seoul have in September?

In September, the average length of the day in Seoul is 12.4h.

How many hours of sunshine does Seoul have in September?

In September, the average sunshine in Seoul, South Korea, is 5.9h.

What is the UV index intensity in September in Seoul?

The average daily maximum UV index in September in Seoul, South Korea, is 7. A UV Index of 6 to 7 symbolizes a high health risk from the exposure to the Sun's UV radiation.
Average temperature in September - Seoul, South Korea
  • Average high temperature in September: 25.8°C

The warmest month (with the highest average high temperature) is August (29.6°C).
The month with the lowest average high temperature is January (1.5°C).

  • Average low temperature in September: 17.2°C

The month with the highest average low temperature is August (22.4°C).
The coldest month (with the lowest average low temperature) is January (-5.9°C).

Average humidity in September - Seoul, South Korea
  • Average humidity in September: 69.2%

The month with the highest relative humidity is July (78.3%).
The month with the lowest relative humidity is April (56.2%).

Average rainfall in September - Seoul, South Korea
  • Average rainfall in September: 169.3mm

The wettest month (with the highest rainfall) is July (394.7mm).
The driest month (with the least rainfall) is January (20.8mm).

Average rainfall days in September - Seoul, South Korea
  • Average rainfall days in September: 9.1 days

The month with the highest number of rainy days is July (16.3 days).
The month with the least rainy days is February (5.8 days).

Average daylight in September / Average sunshine in September - Seoul, South Korea
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 14.7h).
The month with the shortest days is December (Average daylight: 9.6h).

  • Average sunshine in September: 5.9h

The month with the most sunshine is May (Average sunshine: 6.9h).
The month with the least sunshine is July (Average sunshine: 3.9h).

Average UV index in September - Seoul, South Korea
  • Average UV index in September: 7

The month with the highest UV index is July (UV index 10).
Months with the lowest UV index are January and December (UV index 2).