Seoul · September
Run in the morning.
Comfortable average high of 77°F, dipping to 62°F at night. Humidity averages 77% — the limiting factor on most runs. Humidity rises with the sun — morning runs catch the driest, coolest window.
Avg high / low
77° / 62°F
Humidity
77%
Rain days
11/mo
Wind
9 mph
What September feels like in Seoul
Sunrise
06:14
Mid-month average
Sunset
18:40
Mid-month average
Time-of-day breakdown
Morning
Coolest, driest air of the day. The window before sunrise is the most reliable comfortable hour.
Midday
Mild but UV and traffic peak. Workable if you don't mind shifting your pace.
Evening
Warm and runnable. Crowded routes but the air's typically calm.
What to wear running in Seoul in September
The kit for September in Seoul: shorts and a short-sleeve are the standard kit.
September vs the surrounding months
vs August
-7° avg high
-8 rain days
Seoul in August →
September
77°F avg high
11 rain days
Best: morning
vs October
+12° avg high
+3 rain days
Seoul in October →
Frequently Asked Questions
What is the best time of day to run in Seoul in September?+
Morning. Humidity rises with the sun — morning runs catch the driest, coolest window.
What's the average temperature in Seoul in September?+
Average high 77°F, average low 62°F.
How does September compare to surrounding months in Seoul?+
Compared to August (avg high 84°F), September is cooler. Compared to October (avg high 65°F), September is warmer.
Does it rain often in Seoul in September?+
Expect about 11 measurable rain days in September, on average.