September Weather in Rosario, Mexico

Last updated: August 27, 2025

In September, the average temperature in Rosario, Mexico hovers around 27°C (81°F), with a comfortable minimum of 15°C (60°F) and occasional highs reaching 40°C (104°F). Be prepared for some rain as well, with 92 mm (3.6 in) of precipitation spread over 12 days. Expect high humidity too, averaging around 82%, which adds to the tropical feel of the region.

September Temperature in Rosario

In September in Rosario, the average temperature is 27°C (81°F). The maximum can reach 40°C (104°F), while the minimum can drop as low as 15°C (60°F). Be sure to pack accordingly for your travels, as the weather can vary significantly throughout the day.

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

The chart illustrates September temperature patterns in Rosario, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Rosario, September typically has an average temperature of 27°C (81°F), with highs reaching up to 40°C (104°F) and lows dropping to around 15°C (60°F).

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

September Precipitation in Rosario

In Rosario in September, the precipitation amount is 92 mm (3.6 in) over the course of 12 days.

September Precipitation Trends in Rosario

The chart displays monthly precipitation patterns in Rosario, 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 Rosario, September typically receives around 92 mm (3.6 inches) of precipitation spread over approximately 12 days.

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

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Millimeters (mm) Inches (in)

September Humidity in Rosario

In Rosario in September humidity is 82%. With an average temperature of 27°C (81°F), this humidity feels like a heavy blanket wrapping around you, making outdoor activities feel more exhausting, and leaving you longing for the relief of air-conditioned spaces during your travels.

September Average Humidity in Rosario

This chart illustrates the average monthly humidity levels in Rosario, 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 Rosario is approximately 82%, 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 Rosario

In Rosario in September, the maximum UV index reaches 11, which corresponds to an extreme Exposure Category. With a time to burn of just 10 minutes, it's essential to take precautions. For more details, you can check the Hourly UV Index in Rosario.

Maximum UV Index Levels in Rosario for September

The chart shows the monthly maximum UV Index (UVI) for Rosario 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 Rosario typically reaches 11, which falls under the extreme exposure category.

Data source: Rosario 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 Rosario Compares to Other Months

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

This table compares monthly weather conditions in Rosario, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	16°C (61°F)	27 mm (1.1 inches)	74%	high
February Weather	17°C (63°F)	23 mm (0.9 inches)	67%	very high
March Weather	20°C (68°F)	18 mm (0.7 inches)	60%	very high
April Weather	24°C (75°F)	1 mm (0.0 inches)	51%	extreme
May Weather	27°C (80°F)	1 mm (0.0 inches)	47%	extreme
June Weather	30°C (86°F)	33 mm (1.3 inches)	50%	extreme
July Weather	28°C (83°F)	135 mm (5.3 inches)	70%	extreme
August Weather	28°C (82°F)	124 mm (4.9 inches)	81%	extreme
September Weather	27°C (81°F)	92 mm (3.6 inches)	82%	extreme
October Weather	25°C (78°F)	25 mm (1.0 inches)	78%	very high
November Weather	21°C (70°F)	41 mm (1.6 inches)	78%	high
December Weather	17°C (62°F)	33 mm (1.3 inches)	80%	moderate