May Weather in Union, United States

Last updated: June 24, 2025

In Union, United States, the average temperature in May hovers around 10°C (49°F), with a minimum plunge to -5°C (24°F) and maximum highs reaching 28°C (83°F). Expect about 75 mm (2.9 in) of precipitation spread over 12 days, while the air maintains a comfortable average humidity of 77%.

May Temperature in Union

In May in Union, the average temperature is 10°C (49°F). Maximum temperatures can reach 28°C (83°F), while minimum temperatures can dip as low as -5°C (24°F). Overall, it's a time of diverse weather, so travelers should be prepared for a range of conditions.

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

The chart illustrates May temperature patterns in Union, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Union, May typically has an average temperature of 10°C (49°F), with highs reaching up to 28°C (83°F) and lows dropping to around -5°C (24°F).

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

May Precipitation in Union

In Union in May, the total precipitation amount is 75 mm (2.9 in) over the course of 12 days.

May Precipitation Trends in Union

The chart displays monthly precipitation patterns in Union, 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 Union, May typically receives around 75 mm (2.9 inches) of precipitation spread over approximately 12 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 Union

In Union in May, humidity is 77%. With an average temperature of 10°C (49°F), this humidity feels like a chilly, damp embrace that can make outdoor activities quite uncomfortable for traveling, as the cold dampness seeps into clothing and chills the bones, leaving one longing for warmer, drier conditions.

May Average Humidity in Union

This chart illustrates the average monthly humidity levels in Union, 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 Union 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 Union

In Union in May, 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 Union.

Maximum UV Index Levels in Union for May

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

Data source: Union 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 Union Compares to Other Months

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

This table compares monthly weather conditions in Union, showing how May’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-3°C (27°F)	86 mm (3.4 inches)	86%	moderate
February Weather	-3°C (27°F)	132 mm (5.2 inches)	86%	moderate
March Weather	2°C (36°F)	89 mm (3.5 inches)	85%	high
April Weather	5°C (42°F)	83 mm (3.3 inches)	83%	very high
May Weather	10°C (49°F)	75 mm (2.9 inches)	77%	very high
June Weather	14°C (58°F)	41 mm (1.6 inches)	81%	very high
July Weather	20°C (68°F)	2 mm (0.1 inches)	76%	extreme
August Weather	19°C (67°F)	16 mm (0.6 inches)	60%	very high
September Weather	14°C (57°F)	33 mm (1.3 inches)	58%	very high
October Weather	6°C (44°F)	67 mm (2.6 inches)	75%	moderate
November Weather	2°C (35°F)	76 mm (3.0 inches)	85%	moderate
December Weather	-2°C (28°F)	94 mm (3.7 inches)	87%	low