September Weather in Iyo, Japan

Last updated: August 23, 2025

In September, the average temperature in Iyo, Japan is a pleasant 24°C (75°F). Expect lows of 14°C (58°F) and highs reaching up to 33°C (91°F). Rainfall can be anticipated with an average precipitation of 212 mm (8.4 in) spread over 15 days. Don't forget, the humidity hovers around a high 85%, making it feel even warmer.

September Temperature in Iyo

In September in Iyo, the average temperature is 24°C (75°F). Maximums can reach 33°C (91°F), while minimums can drop to as low as 14°C (58°F). This pleasant climate makes it an ideal time for exploring and enjoying outdoor activities in Iyo.

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

The chart illustrates September temperature patterns in Iyo, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Iyo, September typically has an average temperature of 24°C (75°F), with highs reaching up to 33°C (91°F) and lows dropping to around 14°C (58°F).

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

September Precipitation in Iyo

In Iyo in September, the precipitation amount is 212 mm (8.4 in) over a span of 15 days.

September Precipitation Trends in Iyo

The chart displays monthly precipitation patterns in Iyo, 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 Iyo, September typically receives around 212 mm (8.4 inches) of precipitation spread over approximately 15 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 Iyo

In Iyo 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 Iyo

This chart illustrates the average monthly humidity levels in Iyo, 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 Iyo is approximately 85%, 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 Iyo

In Iyo 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 Iyo.

Maximum UV Index Levels in Iyo for September

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

Data source: Iyo 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 Iyo Compares to Other Months

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

This table compares monthly weather conditions in Iyo, 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 (42°F)	60 mm (2.4 inches)	74%	moderate
February Weather	6°C (43°F)	90 mm (3.6 inches)	70%	high
March Weather	10°C (50°F)	129 mm (5.1 inches)	70%	very high
April Weather	14°C (57°F)	135 mm (5.3 inches)	76%	very high
May Weather	18°C (65°F)	153 mm (6.0 inches)	82%	extreme
June Weather	22°C (72°F)	215 mm (8.5 inches)	86%	extreme
July Weather	26°C (79°F)	374 mm (14.7 inches)	91%	extreme
August Weather	27°C (81°F)	197 mm (7.7 inches)	88%	extreme
September Weather	24°C (75°F)	212 mm (8.4 inches)	85%	extreme
October Weather	19°C (66°F)	204 mm (8.0 inches)	82%	very high
November Weather	13°C (55°F)	61 mm (2.4 inches)	79%	high
December Weather	8°C (46°F)	69 mm (2.7 inches)	77%	moderate