September Weather in Koga, Japan

Last updated: August 23, 2025

In September, the average temperature in Koga, Japan is a pleasant 25°C (77°F). However, be prepared for a range, as temperatures can dip to a minimum of 16°C (61°F) and soar to a maximum of 35°C (96°F). This month also sees 216 mm (8.5 in) of precipitation spread over about 16 days, contributing to an average humidity of 84%.

September Temperature in Koga

In September in Koga, the average temperature is 25°C (77°F). Maximum can reach 35°C (96°F) and minimum can be as low as 16°C (61°F). This makes it an ideal time for travelers to enjoy a pleasant climate while exploring the attractions of Koga.

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

The chart illustrates September temperature patterns in Koga, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Koga, September typically has an average temperature of 25°C (77°F), with highs reaching up to 35°C (96°F) and lows dropping to around 16°C (61°F).

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

September Precipitation in Koga

In Koga in September, the precipitation amount is 216 mm (8.5 in) over the course of 16 days.

September Precipitation Trends in Koga

The chart displays monthly precipitation patterns in Koga, 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 Koga, September typically receives around 216 mm (8.5 inches) of precipitation spread over approximately 16 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 Koga

In Koga in September, humidity is 84%. With an average temperature of 25°C (77°F), this humidity feels like a warm, enveloping blanket that clings to your skin, making outdoor activities challenging and prompting travelers to seek shade and stay hydrated.

September Average Humidity in Koga

This chart illustrates the average monthly humidity levels in Koga, 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 Koga is approximately 84%, 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 Koga

In Koga in September, the maximum UV index reaches 11, which corresponds to an extreme Exposure Category. With a time to burn of just 10 minutes, it's essential to take precautions. For more details, you can check the Hourly UV Index in Koga.

Maximum UV Index Levels in Koga for September

The chart shows the monthly maximum UV Index (UVI) for Koga 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 Koga typically reaches 11, which falls under the extreme exposure category.

Data source: Koga 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 Koga Compares to Other Months

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

This table compares monthly weather conditions in Koga, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	7°C (45°F)	57 mm (2.2 inches)	75%	moderate
February Weather	8°C (46°F)	71 mm (2.8 inches)	71%	high
March Weather	12°C (53°F)	120 mm (4.7 inches)	71%	very high
April Weather	16°C (60°F)	107 mm (4.2 inches)	78%	extreme
May Weather	20°C (69°F)	131 mm (5.1 inches)	84%	extreme
June Weather	24°C (75°F)	172 mm (6.8 inches)	86%	extreme
July Weather	27°C (81°F)	300 mm (11.8 inches)	92%	extreme
August Weather	29°C (84°F)	281 mm (11.1 inches)	91%	extreme
September Weather	25°C (77°F)	216 mm (8.5 inches)	84%	extreme
October Weather	20°C (68°F)	107 mm (4.2 inches)	83%	high
November Weather	14°C (58°F)	45 mm (1.8 inches)	81%	high
December Weather	9°C (48°F)	64 mm (2.5 inches)	79%	moderate