Incheon
South Korea
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Incheon, South Korea

The first month of the autumn, September, is also a moderately hot month in Incheon, South Korea, with average temperature fluctuating between 17.5°C (63.5°F) and 25.5°C (77.9°F).

Temperature

In September, the average high-temperature slightly decreases, from a moderately hot 29°C (84.2°F) in August, to a still warm 25.5°C (77.9°F). In September, in Incheon, the average low-temperature is 17.5°C (63.5°F).

Humidity

The average relative humidity in September is 73.1%.

Rainfall

In Incheon, during September, the rain falls for 8.2 days and regularly aggregates up to 153.5mm (6") of precipitation. Throughout the year, there are 101.9 rainfall days, and 1234.5mm (48.6") of precipitation is accumulated.

Sea temperature

In Incheon, in September, the average water temperature is 21.9°C (71.4°F).
Note: Swimming in 21.9°C (71.4°F) is not enjoyable for the majority. Controlling breathing becomes progressively more difficult as surface water temperature decreases below 21°C (69.8°F).

Daylight

The average length of the day in September is 12.4h.

Sunshine

In Incheon, South Korea, the average sunshine in September is 6.6h.

What is the temperature in September in Incheon?

In September, the average high-temperature is 25.5°C (77.9°F), and the average low-temperature is 17.5°C (63.5°F).

What is the average humidity in September in Incheon?

The average relative humidity in September in Incheon is 73.1%.

How many days does it rain in September in Incheon?

In Incheon, South Korea, in September, it is raining for 8.2 days, with typically 153.5mm (6") of accumulated precipitation.

What is the sea temperature in September in Incheon?

In Incheon, in September, the average water temperature is 21.9°C (71.4°F). For most, swimming in 21.9°C (71.4°F) is not an enjoyable activity. Furthermore, controlling your breathing becomes progressively more difficult as the water temperature decreases from 21°C (69.8°F) to 15°C (59°F).

How many hours of daylight does Incheon have in September?

The average length of the day in September is 12.4h.

How long on average sun shines in September in Incheon?

In Incheon, South Korea, the average sunshine in September is 6.6h.
Average temperature in September - Incheon, South Korea
  • Average high temperature in September: 25.5°C

The warmest month (with the highest average high temperature) is August (29°C).
The month with the lowest average high temperature is January (1.7°C).

  • Average low temperature in September: 17.5°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 (-5.4°C).

Average humidity in September - Incheon, South Korea
  • Average humidity in September: 73.1%

The month with the highest relative humidity is July (82.2%).
The month with the lowest relative humidity is January (61.5%).

Average rainfall in September - Incheon, South Korea
  • Average rainfall in September: 153.5mm

The wettest month (with the highest rainfall) is July (319.6mm).
The driest month (with the lowest rainfall) is December (19.3mm).

Average rainfall days in September - Incheon, South Korea
  • Average rainfall days in September: 8.2 days

The month with the highest number of rainy days is July (14.9 days).
The month with the lowest number of rainy days is February (5.3 days).

Average sea temperature in September - Incheon, South Korea
  • Average sea temperature in September: 21.9°C

The best month for swimming (with the highest average sea temperature) is August (23.4°C).
The coldest month (with the lowest average sea temperature) is February (3.3°C).

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

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

  • Average sunshine in September: 6.6h

The month with most sunshine is May (Average sunshine: 7.5h).
The month with least sunshine is July (Average sunshine: 5.1h).