September Weather in Union, Argentina

Last updated: August 22, 2025

In September, the average temperature in Union, Argentina hovers around 15°C (59°F). However, be prepared for a range of temperatures, with a minimum dipping to -4°C (24°F) and a maximum soaring to 35°C (96°F). Expect 37 mm (1.5 in) of precipitation spread over about 5 days, while the average humidity is a comfortable 51%.

September Temperature in Union

In September in Union, the average temperature is 15°C (59°F), with maximums that can reach 35°C (96°F) and minimums that can drop as low as -4°C (24°F). This wide range makes it essential for travelers to prepare for varying weather conditions during their visit.

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

The chart illustrates September 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, September typically has an average temperature of 15°C (59°F), with highs reaching up to 35°C (96°F) and lows dropping to around -4°C (24°F).

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

September Precipitation in Union

In Union in September, the precipitation amount is 37 mm (1.5 in) spread over a period of 5 days.

September Precipitation Trends in Union

The chart displays monthly precipitation patterns in Union, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Union, September typically receives around 37 mm (1.5 inches) of precipitation spread over approximately 5 days.

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

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

September Humidity in Union

In Union in September humidity is 51%. With an average temperature of 15°C (59°F), this humidity feels like a refreshing embrace, making it comfortable for traveling as long as you stay hydrated and take occasional breaks in the shade.

September Average Humidity in Union

This chart illustrates the average monthly humidity levels in Union, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Union is approximately 51%, offering insight into how humid the weather typically is during this month.

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

September UV Index in Union

In Union in September, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Union.

Maximum UV Index Levels in Union for September

The chart shows the monthly maximum UV Index (UVI) for Union in September, 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 September, the maximum UV index in Union typically reaches 8, which falls under the very high exposure category.

Data source: Union September 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 September 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 September’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 September’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