Jeju vs Seoul

Based on sunshine hours, rain days, comfortable temperatures, and humidity levels, Seoul edges ahead as the better destination in September. Seoul offers 9 hours of daily sunshine with only 8 rain days, while Jeju sees 8 sunshine hours and 13 rain days.

Jeju sits in the comfortable travel range at 25°C. Seoul is also comfortable at 25°C.

For travelers who prioritize dry weather, Seoul is the stronger choice in September. Seoul receives 1 more hour of sunshine per day, which matters for sightseeing and outdoor activities.

Jeju reaches an average high of 25°C (77°F) and drops to 22°C (72°F) at night during September. The daily temperature range is 3°C, meaning relatively stable temperatures from day to night.

Seoul averages 25°C (77°F) for the high and 16°C (61°F) for the low, with a daily range of 9°C. The two cities feel quite similar in terms of temperature.

Both cities are in the Northern Hemisphere, so they share the same seasonal pattern in September.

Jeju receives approximately 188 mm of rainfall across 13 rain days during September. You can expect rain roughly every other day.

Seoul sees 123 mm over 8 rain days. That makes Seoul the drier option by 5 rain days and 65 mm of total precipitation.

Humidity also differs: Jeju averages 70% while Seoul sits at 65%. Jeju will feel muggier, especially at higher temperatures.