September weather forecast
Seoul, South Korea

September ushers in the autumn spirit as it transitions from the sweltering summer. The city starts radiating hues of gold and brown, marking the beginning of fall. The comfortable autumn days make it a popular month for touring the city's cultural landmarks. With this transition, the humidity drops to a comfortable 69.2%. October brings in the peak of autumn, with a significant drop in temperature.

Temperature

The advent of September brings a slight shift in average high-temperature, moving from 29.6°C (85.3°F) in August to a still moderately hot 25.8°C (78.4°F). September brings with it a nighttime average temperature of 17.2°C (63°F).

Humidity

In Seoul, the average relative humidity in September is 69.2%.

Rainfall

In Seoul, in September, it is raining for 9.1 days, with typically 169mm (6.65") of accumulated precipitation. In Seoul, during the entire year, the rain falls for 108.8 days and collects up to 1451mm (57.13") of precipitation.

Daylight

In Seoul, South Korea, the average length of the day in September is 12h and 26min.
On the first day of September, sunrise is at 06:02 and sunset at 19:01. On the last day of the month, sunrise is at 06:26 and sunset at 18:17 KST.

Sunshine

In Seoul, 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 threat to health from unsafe exposure to UV radiation for average individuals.
Note: A daily high UV index of 7 in September leads to these guidelines:
Persist with safeguards and heed sun safety doctrines. Keeping sunburn at bay is of prime importance. The hours from 10 a.m. to 4 p.m. have the most intense UV radiation. As much as possible, limit direct sun exposure during this period. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.