May Weather in On, Belgium

Last updated: August 22, 2025

In May, the average temperature in On, Belgium hovers around 13°C (55°F). Expect a minimum of 0°C (32°F) on colder days, while it can heat up to a maximum of 30°C (87°F). Be prepared for some rainfall, as 75 mm (2.9 in) of precipitation is recorded over 14 days, and the average humidity is a notable 77%.

May Temperature in On

In May in On, the average temperature is 13°C (55°F). The maximum can reach 30°C (87°F), while the minimum can be as low as 0°C (32°F). Be sure to pack layers to stay comfortable amidst the varying temperatures during your travels.

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

The chart illustrates May temperature patterns in On, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In On, May typically has an average temperature of 13°C (55°F), with highs reaching up to 30°C (87°F) and lows dropping to around 0°C (32°F).

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

May Precipitation in On

In On in May, the total precipitation amount is 75 mm (2.9 in) accumulated over a period of 14 days.

May Precipitation Trends in On

The chart displays monthly precipitation patterns in On, 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 On, May typically receives around 75 mm (2.9 inches) of precipitation spread over approximately 14 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 On

In On in May humidity is 77%. With an average temperature of 13°C (55°F), this humidity feels like a damp chill in the air, making travel somewhat uncomfortable as the moisture clings to your skin and adds a heavier weight to your clothing, which can sap your energy as you explore.

May Average Humidity in On

This chart illustrates the average monthly humidity levels in On, 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 On is approximately 77%, 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 On

In On in May, the maximum UV index is 7, which corresponds to the high Exposure Category. This means that the time to burn is approximately 25 minutes. For more detailed information, you can check the Hourly UV Index in On.

Maximum UV Index Levels in On for May

The chart shows the monthly maximum UV Index (UVI) for On 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 On typically reaches 7, which falls under the high exposure category.

Data source: On 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 On Compares to Other Months

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

This table compares monthly weather conditions in On, showing how May’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	2°C (37°F)	83 mm (3.3 inches)	91%	low
February Weather	4°C (40°F)	81 mm (3.2 inches)	90%	moderate
March Weather	6°C (43°F)	93 mm (3.7 inches)	87%	moderate
April Weather	9°C (49°F)	45 mm (1.8 inches)	84%	moderate
May Weather	13°C (55°F)	75 mm (2.9 inches)	77%	high
June Weather	17°C (63°F)	83 mm (3.3 inches)	74%	very high
July Weather	18°C (65°F)	83 mm (3.3 inches)	72%	very high
August Weather	18°C (65°F)	80 mm (3.2 inches)	71%	high
September Weather	14°C (58°F)	68 mm (2.7 inches)	81%	moderate
October Weather	11°C (52°F)	92 mm (3.6 inches)	88%	moderate
November Weather	6°C (43°F)	65 mm (2.6 inches)	91%	low
December Weather	4°C (40°F)	123 mm (4.8 inches)	92%	low