April Weather in Iiyama, Japan

Last updated: August 23, 2025

In Iiyama, Japan, the average temperature for April hovers around 9°C (48°F). During this time, temperatures can swing from a chilly -5°C (22°F) at their lowest to a pleasant 27°C (81°F) at their peak. Expect 141 mm (5.5 in) of precipitation spread over 16 days, contributing to an average humidity of 78%.

April Temperature in Iiyama

In April in Iiyama, the average temperature is 9°C (48°F). Maximums can reach 27°C (81°F), while minimums can dip as low as -5°C (22°F). Be prepared for a wide range of temperatures when traveling during this month.

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

The chart illustrates April temperature patterns in Iiyama, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Iiyama, April typically has an average temperature of 9°C (48°F), with highs reaching up to 27°C (81°F) and lows dropping to around -5°C (22°F).

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

April Precipitation in Iiyama

In Iiyama in April, the precipitation amount is 141 mm (5.5 in) accumulated over 16 days.

April Precipitation Trends in Iiyama

The chart displays monthly precipitation patterns in Iiyama, 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 Iiyama, April typically receives around 141 mm (5.5 inches) of precipitation spread over approximately 16 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 Iiyama

In Iiyama in April humidity is 78%. With an average temperature of 9°C (48°F), this humidity feels like a damp chill that clings to your skin, making outdoor excursions less enjoyable as you navigate the damp air.

April Average Humidity in Iiyama

This chart illustrates the average monthly humidity levels in Iiyama, 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 Iiyama is approximately 78%, 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 Iiyama

In Iiyama in April, the maximum UV index is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the Hourly UV Index in Iiyama.

Maximum UV Index Levels in Iiyama for April

The chart shows the monthly maximum UV Index (UVI) for Iiyama 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 Iiyama typically reaches 9, which falls under the very high exposure category.

Data source: Iiyama 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 Iiyama Compares to Other Months

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

This table compares monthly weather conditions in Iiyama, showing how April’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-2°C (29°F)	144 mm (5.7 inches)	88%	moderate
February Weather	-1°C (30°F)	129 mm (5.1 inches)	86%	high
March Weather	4°C (39°F)	133 mm (5.2 inches)	81%	very high
April Weather	9°C (48°F)	141 mm (5.5 inches)	78%	very high
May Weather	15°C (59°F)	160 mm (6.3 inches)	81%	extreme
June Weather	18°C (65°F)	171 mm (6.7 inches)	88%	extreme
July Weather	22°C (73°F)	341 mm (13.4 inches)	92%	extreme
August Weather	24°C (75°F)	198 mm (7.8 inches)	92%	extreme
September Weather	19°C (67°F)	194 mm (7.6 inches)	89%	very high
October Weather	13°C (56°F)	217 mm (8.5 inches)	87%	high
November Weather	7°C (44°F)	94 mm (3.7 inches)	85%	moderate
December Weather	1°C (34°F)	151 mm (6.0 inches)	86%	moderate