September Weather in Rumoi, Japan

Last updated: August 23, 2025

In September, the average temperature in Rumoi, Japan is a comfortable 18°C (64°F), making it an ideal time for outdoor activities. Expect minimum temperatures around 7°C (45°F), while the highs can reach up to 28°C (82°F). However, be prepared for a bit of rain, as precipitation averages 90 mm (3.6 in) over 12 days. With an average humidity of 88%, it’s advisable to stay hydrated and embrace the refreshing weather!

September Temperature in Rumoi

In September in Rumoi, the average temperature is 18°C (64°F). The maximum can reach 28°C (82°F) and the minimum can be as low as 7°C (45°F). This comfortable climate makes Rumoi an ideal destination for outdoor activities and exploration during this time of year.

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

The chart illustrates September temperature patterns in Rumoi, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Rumoi, September typically has an average temperature of 18°C (64°F), with highs reaching up to 28°C (82°F) and lows dropping to around 7°C (45°F).

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

September Precipitation in Rumoi

In Rumoi in September, the precipitation amount is 90 mm (3.6 in) spread over 12 days.

September Precipitation Trends in Rumoi

The chart displays monthly precipitation patterns in Rumoi, 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 Rumoi, September typically receives around 90 mm (3.6 inches) of precipitation spread over approximately 12 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 Rumoi

In Rumoi in September, humidity is 88%. With an average temperature of 18°C (64°F), this humidity feels like you’re walking through a warm, enveloping mist, making every step slightly weighted but also refreshing, ideal for leisurely exploration but challenging for strenuous activities.

September Average Humidity in Rumoi

This chart illustrates the average monthly humidity levels in Rumoi, 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 Rumoi is approximately 88%, 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 Rumoi

In Rumoi in September, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Rumoi.

Maximum UV Index Levels in Rumoi for September

The chart shows the monthly maximum UV Index (UVI) for Rumoi 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 Rumoi typically reaches 8, which falls under the very high exposure category.

Data source: Rumoi 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 Rumoi Compares to Other Months

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

This table compares monthly weather conditions in Rumoi, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-5°C (22°F)	70 mm (2.8 inches)	84%	low
February Weather	-4°C (24°F)	84 mm (3.3 inches)	83%	moderate
March Weather	0°C (33°F)	84 mm (3.3 inches)	81%	moderate
April Weather	6°C (42°F)	67 mm (2.6 inches)	81%	high
May Weather	11°C (52°F)	89 mm (3.5 inches)	86%	very high
June Weather	15°C (59°F)	94 mm (3.7 inches)	87%	very high
July Weather	21°C (69°F)	103 mm (4.0 inches)	93%	very high
August Weather	21°C (70°F)	171 mm (6.7 inches)	95%	very high
September Weather	18°C (64°F)	90 mm (3.6 inches)	88%	very high
October Weather	12°C (53°F)	147 mm (5.8 inches)	83%	moderate
November Weather	5°C (41°F)	152 mm (6.0 inches)	79%	moderate
December Weather	-2°C (28°F)	132 mm (5.2 inches)	80%	low