Weather Comparison
Side-by-side weather comparison for September
| Metric | Hong Kong | Seoul | Better |
|---|---|---|---|
| Average HighHigher is warmer | 29°C (84°F)▲ | 25°C (77°F) | Hong Kong |
| Average LowHigher is milder | 25°C (77°F)▲ | 16°C (61°F) | Hong Kong |
| Rain DaysFewer is drier | 17 days | 8 days▲ | Seoul |
| PrecipitationLess is drier | 215 mm | 123 mm▲ | Seoul |
| Sunshine HoursMore is sunnier | 10h/day▲ | 9h/day | Hong Kong |
| HumidityLower is more comfortable | 78% | 65%▲ | Seoul |
| UV IndexLower is safer | 6 | 6 | Tie |
| Wind SpeedCalmer is better | 16 km/h | 13 km/h▲ | 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 Hong Kong sees 10 sunshine hours and 17 rain days.
Hong Kong can feel quite hot at 29°C, so plan for heat. Seoul is also comfortable at 25°C.
For travelers who prioritize dry weather, Seoul is the stronger choice in September. Hong Kong receives 1 more hour of sunshine per day, which matters for sightseeing and outdoor activities.
Hong Kong reaches an average high of 29°C (84°F) and drops to 25°C (77°F) at night during September. The daily temperature range is 4°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 4°C difference is noticeable but not dramatic.
Both cities are in the Northern Hemisphere, so they share the same seasonal pattern in September.
Hong Kong receives approximately 215 mm of rainfall across 17 rain days during September. Rain is frequent, so waterproof gear is essential.
Seoul sees 123 mm over 8 rain days. That makes Seoul the drier option by 9 rain days and 92 mm of total precipitation.
Humidity also differs: Hong Kong averages 78% while Seoul sits at 65%. Hong Kong will feel muggier, especially at higher temperatures.
Highs of 29°C, lows of 25°C, 17 rain days
Highs of 25°C, lows of 16°C, 8 rain days
The table below shows average high temperatures and rain days for every month. September is highlighted for quick reference.
| Month | Hong Kong | Seoul | ||
|---|---|---|---|---|
| High | Rain | High | Rain | |
| Jan | 19°C | 4d | 1°C | 4d |
| Feb | 20°C | 6d | 4°C | 4d |
| Mar | 22°C | 10d | 10°C | 6d |
| Apr | 25°C | 14d | 17°C | 7d |
| May | 28°C | 20d | 22°C | 8d |
| Jun | 29°C | 24d | 26°C | 9d |
| Jul | 30°C | 24d | 28°C | 17d |
| Aug | 30°C | 24d | 29°C | 16d |
| Sep | 29°C | 17d | 25°C | 8d |
| Oct | 27°C | 7d | 19°C | 5d |
| Nov | 24°C | 5d | 11°C | 7d |
| Dec | 20°C | 4d | 3°C | 5d |
Hong Kong Weather in September
Full forecast, packing tips, and activities
Seoul Weather in September
Full forecast, packing tips, and activities