September Weather in Nankoku, Japan

Last updated: August 23, 2025

In Nankoku, Japan, the average temperature in September hovers around 25°C (77°F), creating a pleasant climate for outdoor activities. However, temperatures can vary, with a minimum of 16°C (61°F) and a maximum soaring to 32°C (89°F). Expect considerable rainfall, with an average precipitation of 262 mm (10.3 in) spread over 18 days, accompanied by an average humidity of 85%. Whether you're exploring the sights or relaxing in a café, be prepared for a mix of warmth and moisture!

September Temperature in Nankoku

In September in Nankoku, the average temperature is 25°C (77°F). Maximum temperatures can reach 32°C (89°F), while minimums can drop to as low as 16°C (61°F). This pleasant climate makes Nankoku a great destination for outdoor adventures and sightseeing during this time.

September Weather in Nankoku: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Nankoku, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Nankoku, September typically has an average temperature of 25°C (77°F), with highs reaching up to 32°C (89°F) and lows dropping to around 16°C (61°F).

Data source: Temperature data for Nankoku generated using information from the Copernicus Climate Change Service.

September Precipitation in Nankoku

In Nankoku in September, the total precipitation amount is 262 mm (10.3 in), which falls over the course of 18 days.

September Precipitation Trends in Nankoku

The chart displays monthly precipitation patterns in Nankoku, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Nankoku, September typically receives around 262 mm (10.3 inches) of precipitation spread over approximately 18 days.

Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

September Humidity in Nankoku

In Nankoku in September, humidity is 85%. With an average temperature of 25°C (77°F), this humidity feels like a warm, heavy blanket wrapping around you, making every outdoor excursion feel both stifling and sticky, requiring frequent breaks in the shade to stay comfortable while exploring.

September Average Humidity in Nankoku

This chart illustrates the average monthly humidity levels in Nankoku, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Nankoku is approximately 85%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Nankoku

In Nankoku in September, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in Nankoku.

Maximum UV Index Levels in Nankoku for September

The chart shows the monthly maximum UV Index (UVI) for Nankoku in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In September, the maximum UV index in Nankoku typically reaches 10, which falls under the very high exposure category.

Data source: Nankoku September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

Extreme (11+): Avoid the sun, stay in shade.
Very High (8-10): Limit sun exposure.
High (6-7): Use SPF 30+ and protective clothing.
Moderate (3-5): Midday shade recommended.
Low (0-2): No protection needed.

How September Weather in Nankoku Compares to Other Months

Weather in Nankoku varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Nankoku, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Nankoku, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	8°C (46°F)	54 mm (2.1 inches)	74%	moderate
February Weather	8°C (47°F)	86 mm (3.4 inches)	70%	high
March Weather	12°C (54°F)	147 mm (5.8 inches)	70%	very high
April Weather	15°C (60°F)	170 mm (6.7 inches)	76%	extreme
May Weather	19°C (67°F)	206 mm (8.1 inches)	82%	extreme
June Weather	22°C (73°F)	286 mm (11.3 inches)	86%	extreme
July Weather	26°C (79°F)	523 mm (20.6 inches)	91%	extreme
August Weather	27°C (82°F)	298 mm (11.7 inches)	88%	extreme
September Weather	25°C (77°F)	262 mm (10.3 inches)	85%	very high
October Weather	20°C (69°F)	251 mm (9.9 inches)	82%	high
November Weather	15°C (59°F)	63 mm (2.5 inches)	79%	high
December Weather	10°C (50°F)	67 mm (2.7 inches)	77%	moderate