nomadseason

September Weather in Kosaka, Japan

Last updated: August 23, 2025

In September, the average temperature in Kosaka, Japan is around 18°C (65°F). Visitors can expect temperature fluctuations, with a minimum of 5°C (41°F) and a maximum of 33°C (91°F). During this month, precipitation reaches approximately 137 mm (5.4 in) over 13 days, contributing to the high humidity level of 89%.

September Temperature in Kosaka

In September in Kosaka, the average temperature is 18°C (65°F). The maximum can reach 33°C (91°F), while the minimum can drop as low as 5°C (41°F). Overall, it's a great time to explore Kosaka with comfortable temperatures and a variety of weather experiences.

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

The chart illustrates September temperature patterns in Kosaka, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Kosaka, September typically has an average temperature of 18°C (65°F), with highs reaching up to 33°C (91°F) and lows dropping to around 5°C (41°F).
JanFebMarAprMayJunJulAugSepOctNovDec262735455763717265534230
Data source: Temperature data for Kosaka generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Kosaka

In Kosaka in September, the total precipitation amount reaches 137 mm (5.4 in) over the course of 13 days.

September Precipitation Trends in Kosaka

The chart displays monthly precipitation patterns in Kosaka, 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 Kosaka, September typically receives around 137 mm (5.4 inches) of precipitation spread over approximately 13 days.
JanFebMarAprMayJunJulAugSepOctNovDec78108107127116142168179137166100114
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Kosaka

In Kosaka in September, humidity is 89%. With an average temperature of 18°C (65°F), this humidity feels like wrapping yourself in a damp blanket while traveling, making it sticky and uncomfortable for outdoor activities.

September Average Humidity in Kosaka

This chart illustrates the average monthly humidity levels in Kosaka, 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 Kosaka is approximately 89%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec79%78%77%78%86%91%95%97%89%82%78%77%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Kosaka

In Kosaka in September, the maximum UV index is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the Hourly UV Index in Kosaka.

Maximum UV Index Levels in Kosaka for September

The chart shows the monthly maximum UV Index (UVI) for Kosaka 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 Kosaka typically reaches 9, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec346891010119642
Data source: Kosaka 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 Kosaka Compares to Other Months

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

This table compares monthly weather conditions in Kosaka, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-3°C (26°F)78 mm (3.1 inches)79%moderate
February Weather-3°C (28°F)108 mm (4.3 inches)78%moderate
March Weather2°C (35°F)107 mm (4.2 inches)77%high
April Weather7°C (45°F)127 mm (5.0 inches)78%very high
May Weather14°C (57°F)116 mm (4.6 inches)86%very high
June Weather17°C (63°F)142 mm (5.6 inches)91%very high
July Weather22°C (71°F)168 mm (6.6 inches)95%very high
August Weather22°C (73°F)179 mm (7.1 inches)97%extreme
September Weather18°C (65°F)137 mm (5.4 inches)89%very high
October Weather12°C (54°F)166 mm (6.5 inches)81%high
November Weather6°C (42°F)100 mm (4.0 inches)78%moderate
December Weather-1°C (30°F)114 mm (4.5 inches)77%low

Compare Kosaka's Climate with Cities Worldwide