May Weather in Grignon, France

Last updated: August 23, 2025

In May, the average temperature in Grignon, France is a cool 9°C (48°F), with extremes ranging from a brisk -8°C (18°F) to a surprisingly warm 25°C (77°F). Expect a noteworthy 203 mm (8.0 in) of precipitation over approximately 20 days, contributing to an average humidity of 78%.

May Temperature in Grignon

In May in Grignon, the average temperature is 9°C (48°F), with maximums reaching 25°C (77°F) and minimums plummeting as low as -8°C (18°F). Pack accordingly to enjoy a comfortable visit, as the weather can vary greatly during this time.

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

The chart illustrates May temperature patterns in Grignon, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Grignon, May typically has an average temperature of 9°C (48°F), with highs reaching up to 25°C (77°F) and lows dropping to around -8°C (18°F).

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

May Precipitation in Grignon

In Grignon in May, the precipitation amount is 203 mm (8.0 in) spread over 20 days.

May Precipitation Trends in Grignon

The chart displays monthly precipitation patterns in Grignon, 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 Grignon, May typically receives around 203 mm (8.0 inches) of precipitation spread over approximately 20 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 Grignon

In Grignon in May 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.

May Average Humidity in Grignon

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

In Grignon in May, 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 Grignon.

Maximum UV Index Levels in Grignon for May

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

Data source: Grignon 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 Grignon Compares to Other Months

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

This table compares monthly weather conditions in Grignon, 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 (24°F)	153 mm (6.0 inches)	91%	moderate
February Weather	-1°C (30°F)	124 mm (4.9 inches)	87%	moderate
March Weather	2°C (35°F)	160 mm (6.3 inches)	84%	high
April Weather	5°C (42°F)	82 mm (3.2 inches)	83%	very high
May Weather	9°C (48°F)	203 mm (8.0 inches)	78%	very high
June Weather	14°C (57°F)	144 mm (5.7 inches)	75%	very high
July Weather	16°C (61°F)	103 mm (4.0 inches)	72%	very high
August Weather	15°C (60°F)	107 mm (4.2 inches)	63%	very high
September Weather	11°C (53°F)	85 mm (3.4 inches)	73%	high
October Weather	7°C (45°F)	115 mm (4.5 inches)	89%	moderate
November Weather	1°C (35°F)	114 mm (4.5 inches)	90%	moderate
December Weather	-3°C (27°F)	264 mm (10.4 inches)	90%	low