December Weather in Union, Argentina

Last updated: August 22, 2025

In Union, Argentina, the average temperature in December hovers around 25°C (76°F), offering a pleasant climate. However, temperatures can fluctuate, with a minimum of 11°C (52°F) and soaring up to a sweltering 42°C (109°F). Along with this warmth, anticipate 58 mm (2.3 in) of precipitation over about 7 days, and enjoy a comfortable average humidity level of 44%.

December Temperature in Union

In December in Union, the average temperature is 25°C (76°F). Maximums can reach up to 42°C (109°F), while minimums can drop to as low as 11°C (52°F). Be prepared for a wide range of temperatures, making it essential to pack both light clothing and warmer layers for your trip.

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

The chart illustrates December 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, December typically has an average temperature of 25°C (76°F), with highs reaching up to 42°C (109°F) and lows dropping to around 11°C (52°F).

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

December Precipitation in Union

In Union in December, the precipitation amount is 58 mm (2.3 in) over the course of 7 days.

December Precipitation Trends in Union

The chart displays monthly precipitation patterns in Union, with values for each month alongside December’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how December’s conditions compare to those of other months. In Union, December typically receives around 58 mm (2.3 inches) of precipitation spread over approximately 7 days.

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

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Millimeters (mm) Inches (in)

December Humidity in Union

In Union in December humidity is 44%. With an average temperature of 25°C (76°F), this humidity feels like a warm embrace, making it comfortable for exploring outdoor attractions while maintaining a pleasant breeze that keeps travel enjoyable.

December Average Humidity in Union

This chart illustrates the average monthly humidity levels in Union, with December’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In December, average humidity in Union is approximately 44%, offering insight into how humid the weather typically is during this month.

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

December UV Index in Union

In Union in December, the maximum UV index is 14, which corresponds to an extreme Exposure Category. The time to burn is just 10 minutes, so it's crucial to take precautions. For the detailed hourly UV index in Union, you can check here.

Maximum UV Index Levels in Union for December

The chart shows the monthly maximum UV Index (UVI) for Union in December, 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 December, the maximum UV index in Union typically reaches 14, which falls under the extreme exposure category.

Data source: Union December 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 December 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 December’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 December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	26°C (79°F)	54 mm (2.1 inches)	44%	extreme
February Weather	25°C (77°F)	28 mm (1.1 inches)	52%	extreme
March Weather	21°C (71°F)	65 mm (2.6 inches)	57%	extreme
April Weather	18°C (64°F)	57 mm (2.2 inches)	67%	high
May Weather	13°C (56°F)	38 mm (1.5 inches)	70%	moderate
June Weather	9°C (48°F)	24 mm (0.9 inches)	61%	moderate
July Weather	9°C (48°F)	17 mm (0.7 inches)	60%	moderate
August Weather	12°C (53°F)	10 mm (0.4 inches)	55%	high
September Weather	15°C (59°F)	37 mm (1.5 inches)	51%	very high
October Weather	18°C (64°F)	37 mm (1.5 inches)	47%	extreme
November Weather	21°C (71°F)	66 mm (2.6 inches)	46%	extreme
December Weather	25°C (76°F)	58 mm (2.3 inches)	44%	extreme