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September Weather in Ishii, Japan

Last updated: August 23, 2025

In Ishii, Japan, the average temperature in September hovers around 24°C (75°F), with minimums dipping to 16°C (62°F) and maximums reaching up to 31°C (89°F). This month is characterized by an average precipitation of 294 mm (11.6 in) spread over 18 days, contributing to a high average humidity of 85%. Whether you're planning a visit or simply curious, September in Ishii offers a unique blend of warmth and wetness.

September Temperature in Ishii

In September in Ishii, the average temperature is 24°C (75°F), with maximums reaching up to 31°C (89°F) and minimums dipping as low as 16°C (62°F). This makes it an ideal destination for travelers seeking pleasant weather and outdoor activities.

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

The chart illustrates September temperature patterns in Ishii, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Ishii, September typically has an average temperature of 24°C (75°F), with highs reaching up to 31°C (89°F) and lows dropping to around 16°C (62°F).
JanFebMarAprMayJunJulAugSepOctNovDec434450576571788175665747
Data source: Temperature data for Ishii 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 Ishii

In Ishii in September, the precipitation amount is 294 mm (11.6 in) over a span of 18 days.

September Precipitation Trends in Ishii

The chart displays monthly precipitation patterns in Ishii, 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 Ishii, September typically receives around 294 mm (11.6 inches) of precipitation spread over approximately 18 days.
JanFebMarAprMayJunJulAugSepOctNovDec60711371451842343782262943606564
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Ishii

In Ishii in September humidity is 85%. With an average temperature of 24°C (75°F), this humidity feels like walking through a warm, heavy blanket, making travel feel sluggish and draining as you navigate through the thick, muggy air.

September Average Humidity in Ishii

This chart illustrates the average monthly humidity levels in Ishii, 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 Ishii is approximately 85%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec74%70%70%76%83%86%91%88%85%82%79%77%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Ishii

In Ishii 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 Ishii.

Maximum UV Index Levels in Ishii for September

The chart shows the monthly maximum UV Index (UVI) for Ishii 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 Ishii typically reaches 10, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec468111112121210764
Data source: Ishii 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 Ishii Compares to Other Months

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

This table compares monthly weather conditions in Ishii, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather6°C (43°F)60 mm (2.4 inches)74%moderate
February Weather7°C (44°F)71 mm (2.8 inches)70%high
March Weather10°C (51°F)137 mm (5.4 inches)70%very high
April Weather14°C (57°F)145 mm (5.7 inches)76%extreme
May Weather18°C (65°F)184 mm (7.3 inches)82%extreme
June Weather21°C (71°F)234 mm (9.2 inches)86%extreme
July Weather26°C (78°F)378 mm (14.9 inches)91%extreme
August Weather27°C (81°F)226 mm (8.9 inches)88%extreme
September Weather24°C (75°F)294 mm (11.6 inches)85%very high
October Weather19°C (67°F)360 mm (14.2 inches)82%high
November Weather14°C (57°F)65 mm (2.5 inches)79%high
December Weather9°C (48°F)64 mm (2.5 inches)77%moderate

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