April Weather in Isumi, Japan

Last updated: August 23, 2025

In April, the average temperature in Isumi, Japan hovers around 15°C (59°F), with a minimum of 6°C (43°F) and a pleasant maximum of 21°C (71°F). Expect 117 mm (4.6 in) of precipitation over approximately 11 days, contributing to an average humidity of 73%. Get ready for a mix of mild weather and occasional showers!

April Temperature in Isumi

In April in Isumi, the average temperature is 15°C (59°F), with maximums reaching 21°C (71°F) and minimums dropping to as low as 6°C (43°F). This mild climate makes it an ideal time to explore the outdoors and enjoy local attractions.

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

The chart illustrates April 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, April typically has an average temperature of 15°C (59°F), with highs reaching up to 21°C (71°F) and lows dropping to around 6°C (43°F).

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

April Precipitation in Isumi

In Isumi in April, the total precipitation amount reaches 117 mm (4.6 in) over the course of 11 days.

April Precipitation Trends in Isumi

The chart displays monthly precipitation patterns in Isumi, with values for each month alongside April’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how April’s conditions compare to those of other months. In Isumi, April typically receives around 117 mm (4.6 inches) of precipitation spread over approximately 11 days.

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

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Millimeters (mm) Inches (in)

April Humidity in Isumi

In Isumi in April humidity is 73%. With an average temperature of 15°C (59°F), this humidity feels like a mild discomfort, making sightseeing a bit sticky and requiring travelers to stay hydrated and take breaks in the shade.

April Average Humidity in Isumi

This chart illustrates the average monthly humidity levels in Isumi, with April’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In April, average humidity in Isumi is approximately 73%, offering insight into how humid the weather typically is during this month.

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

April UV Index in Isumi

In Isumi in April, 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 Isumi.

Maximum UV Index Levels in Isumi for April

The chart shows the monthly maximum UV Index (UVI) for Isumi in April, 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 April, the maximum UV index in Isumi typically reaches 10, which falls under the very high exposure category.

Data source: Isumi April 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 April 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 April’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 April’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