May Weather in Isumi, Japan

Last updated: August 23, 2025

In May, the average temperature in Isumi, Japan hovers around 19°C (67°F), offering a pleasant climate. Expect a minimum of 12°C (55°F) and a maximum of 25°C (77°F), making it ideal for various outdoor activities. However, be prepared for rain, as 140 mm (5.5 in) of precipitation may fall over 11 days during the month. With an average humidity of 81%, it's advisable to stay hydrated and enjoy the lush scenery!

May Temperature in Isumi

In May in Isumi, the average temperature is 19°C (67°F). Maximum temperatures can reach 25°C (77°F), while minimum temperatures can drop as low as 12°C (55°F). This climate makes Isumi an ideal destination for travelers seeking mild and comfortable weather.

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

The chart illustrates May temperature patterns in Isumi, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Isumi, May typically has an average temperature of 19°C (67°F), with highs reaching up to 25°C (77°F) and lows dropping to around 12°C (55°F).

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

May Precipitation in Isumi

In Isumi in May, the total precipitation amount is 140 mm (5.5 in), occurring over a span of 11 days.

May Precipitation Trends in Isumi

The chart displays monthly precipitation patterns in Isumi, 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 Isumi, May typically receives around 140 mm (5.5 inches) of precipitation spread over approximately 11 days.

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

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Millimeters (mm) Inches (in)

May Humidity in Isumi

In Isumi in May humidity is 81%. With an average temperature of 19°C (67°F), this humidity feels like a heavy blanket enveloping you, making travel somewhat uncomfortable as sweat clings to your skin and the air feels thick, prompting you to seek shade and hydration frequently.

May Average Humidity in Isumi

This chart illustrates the average monthly humidity levels in Isumi, 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 Isumi is approximately 81%, 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 Isumi

In Isumi 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 Isumi.

Maximum UV Index Levels in Isumi for May

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

Data source: Isumi 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 Isumi Compares to Other Months

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

This table compares monthly weather conditions in Isumi, showing how May’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	9°C (48°F)	77 mm (3.0 inches)	70%	moderate
February Weather	9°C (48°F)	68 mm (2.7 inches)	69%	moderate
March Weather	12°C (54°F)	180 mm (7.1 inches)	68%	very high
April Weather	15°C (59°F)	117 mm (4.6 inches)	73%	very high
May Weather	19°C (67°F)	140 mm (5.5 inches)	81%	extreme
June Weather	22°C (72°F)	206 mm (8.1 inches)	88%	extreme
July Weather	25°C (78°F)	206 mm (8.1 inches)	94%	extreme
August Weather	27°C (81°F)	113 mm (4.5 inches)	87%	extreme
September Weather	25°C (77°F)	214 mm (8.4 inches)	83%	very high
October Weather	21°C (69°F)	292 mm (11.5 inches)	78%	high
November Weather	16°C (62°F)	142 mm (5.6 inches)	74%	moderate
December Weather	11°C (53°F)	114 mm (4.5 inches)	72%	moderate