May Weather in Niihama, Japan

Last updated: August 23, 2025

In Niihama, Japan, the average temperature in May hovers around 18°C (65°F). Expect a minimum of 9°C (48°F) and a maximum of 26°C (80°F), making it quite pleasant overall. However, be prepared for rainy days, with an average precipitation of 148 mm (5.8 in) spread over 11 days. With an average humidity of 82%, the air can feel quite tropical, so pack accordingly!

May Temperature in Niihama

In May in Niihama, the average temperature is 18°C (65°F). Maximums can reach 26°C (80°F), and minimums can be as low as 9°C (48°F). This pleasant climate makes it a great time to explore outdoor activities and enjoy the local scenery.

May Weather in Niihama: Daily Temperature Highs, Lows, and Averages

The chart illustrates May temperature patterns in Niihama, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Niihama, May typically has an average temperature of 18°C (65°F), with highs reaching up to 26°C (80°F) and lows dropping to around 9°C (48°F).

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

May Precipitation in Niihama

In Niihama in May, the precipitation amount is 148 mm (5.8 in) spread over a duration of 11 days.

May Precipitation Trends in Niihama

The chart displays monthly precipitation patterns in Niihama, with values for each month alongside May’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how May’s conditions compare to those of other months. In Niihama, May typically receives around 148 mm (5.8 inches) of precipitation spread over approximately 11 days.

Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

May Humidity in Niihama

In Niihama in May, humidity is 82%. With an average temperature of 18°C (65°F), this humidity feels like a warm, sticky embrace that can quickly leave travelers feeling fatigued and in need of frequent breaks to stay refreshed and hydrated.

May Average Humidity in Niihama

This chart illustrates the average monthly humidity levels in Niihama, with May’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In May, average humidity in Niihama is approximately 82%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in Niihama

In Niihama in May, 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 Niihama.

Maximum UV Index Levels in Niihama for May

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

Data source: Niihama May 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 May Weather in Niihama Compares to Other Months

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

This table compares monthly weather conditions in Niihama, showing how May’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	5°C (42°F)	65 mm (2.6 inches)	74%	moderate
February Weather	6°C (43°F)	85 mm (3.4 inches)	70%	high
March Weather	9°C (49°F)	129 mm (5.1 inches)	70%	very high
April Weather	13°C (57°F)	142 mm (5.6 inches)	76%	very high
May Weather	18°C (65°F)	148 mm (5.8 inches)	82%	extreme
June Weather	22°C (71°F)	199 mm (7.8 inches)	86%	extreme
July Weather	26°C (79°F)	357 mm (14.1 inches)	91%	extreme
August Weather	27°C (82°F)	181 mm (7.1 inches)	88%	extreme
September Weather	24°C (75°F)	237 mm (9.3 inches)	85%	very high
October Weather	19°C (66°F)	253 mm (10.0 inches)	82%	high
November Weather	13°C (56°F)	69 mm (2.7 inches)	79%	high
December Weather	8°C (46°F)	80 mm (3.1 inches)	77%	moderate