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September Weather in Oyama, Japan

Last updated: August 23, 2025

In Oyama, Japan, the average temperature in September hovers around 25°C (78°F). Expect a minimum of 21°C (69°F) and a maximum of 29°C (85°F), making it a warm month overall. However, be prepared for some rain, as 255 mm (10.0 in) of precipitation is likely over 19 days. Additionally, the air tends to be quite humid, with an average humidity level of 86%.

September Temperature in Oyama

In September in Oyama, the average temperature is 25°C (78°F). Maximum temperatures can reach 29°C (85°F), while the minimum can drop as low as 21°C (69°F). This pleasant climate makes Oyama an ideal destination for travelers seeking comfortable weather.

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

The chart illustrates September temperature patterns in Oyama, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Oyama, September typically has an average temperature of 25°C (78°F), with highs reaching up to 29°C (85°F) and lows dropping to around 21°C (69°F).
JanFebMarAprMayJunJulAugSepOctNovDec495055606772788178716354
Data source: Temperature data for Oyama generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Oyama

In Oyama in September, the precipitation amount is 255 mm (10.0 in) over the course of 19 days.

September Precipitation Trends in Oyama

The chart displays monthly precipitation patterns in Oyama, 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 Oyama, September typically receives around 255 mm (10.0 inches) of precipitation spread over approximately 19 days.
JanFebMarAprMayJunJulAugSepOctNovDec709318916421330236316325532813799
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Oyama

In Oyama in September, humidity is 86%. With an average temperature of 25°C (78°F), this humidity feels like a warm, damp blanket wrapping around you, making outdoor activities challenging and potentially uncomfortable for traveling.

September Average Humidity in Oyama

This chart illustrates the average monthly humidity levels in Oyama, 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 Oyama is approximately 86%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec76%74%70%74%82%88%93%90%86%83%80%78%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Oyama

In Oyama 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 Oyama.

Maximum UV Index Levels in Oyama for September

The chart shows the monthly maximum UV Index (UVI) for Oyama 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 Oyama typically reaches 10, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec468101111121110754
Data source: Oyama 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 Oyama Compares to Other Months

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

This table compares monthly weather conditions in Oyama, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather10°C (49°F)70 mm (2.8 inches)76%moderate
February Weather10°C (50°F)93 mm (3.7 inches)74%high
March Weather13°C (55°F)189 mm (7.4 inches)70%very high
April Weather16°C (60°F)164 mm (6.4 inches)74%very high
May Weather19°C (67°F)213 mm (8.4 inches)81%extreme
June Weather22°C (72°F)302 mm (11.9 inches)88%extreme
July Weather25°C (78°F)363 mm (14.3 inches)93%extreme
August Weather27°C (81°F)163 mm (6.4 inches)90%extreme
September Weather25°C (78°F)255 mm (10.0 inches)86%very high
October Weather22°C (71°F)328 mm (12.9 inches)83%high
November Weather17°C (63°F)137 mm (5.4 inches)80%moderate
December Weather12°C (55°F)99 mm (3.9 inches)78%moderate

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