September Weather in Rio Grande City, United States

Last updated: June 24, 2025

In September, the average temperature in Rio Grande City, United States is a warm 29°C (84°F), with fluctuations ranging from a comfortable 18°C (65°F) at night to a scorching 41°C (106°F) during the day. Expect 97 mm (3.8 in) of precipitation over about 9 days, contributing to an average humidity of 73%. Perfect for enjoying those tropical vibes!

September Temperature in Rio Grande City

In September in Rio Grande City, the average temperature is 29°C (84°F). Maximum temperatures can reach up to 41°C (106°F), while minimums can drop as low as 18°C (65°F). Travelers should be prepared for a warm climate, with hot days and cooler nights.

September Weather in Rio Grande City: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Rio Grande City, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Rio Grande City, September typically has an average temperature of 29°C (84°F), with highs reaching up to 41°C (106°F) and lows dropping to around 18°C (65°F).

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

September Precipitation in Rio Grande City

In Rio Grande City in September, the total precipitation amount reaches 97 mm (3.8 in) over the course of 9 days.

September Precipitation Trends in Rio Grande City

The chart displays monthly precipitation patterns in Rio Grande City, 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 Rio Grande City, September typically receives around 97 mm (3.8 inches) of precipitation spread over approximately 9 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 Rio Grande City

In Rio Grande City in September, humidity is 73%. With an average temperature of 29°C (84°F), this humidity feels like a warm blanket wrapped around you, making travel slightly uncomfortable as you sweat and seek shade, yet still inviting you to explore the vibrant local culture and activities.

September Average Humidity in Rio Grande City

This chart illustrates the average monthly humidity levels in Rio Grande City, 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 Rio Grande City is approximately 73%, 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 Rio Grande City

In Rio Grande City 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 Rio Grande City.

Maximum UV Index Levels in Rio Grande City for September

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

Data source: Rio Grande City 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 Rio Grande City Compares to Other Months

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

This table compares monthly weather conditions in Rio Grande City, 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)	18 mm (0.7 inches)	83%	high
February Weather	18°C (65°F)	18 mm (0.7 inches)	79%	very high
March Weather	22°C (72°F)	29 mm (1.1 inches)	76%	very high
April Weather	25°C (78°F)	32 mm (1.3 inches)	77%	extreme
May Weather	28°C (83°F)	77 mm (3.0 inches)	80%	extreme
June Weather	30°C (86°F)	79 mm (3.1 inches)	73%	extreme
July Weather	30°C (87°F)	73 mm (2.9 inches)	66%	extreme
August Weather	31°C (89°F)	16 mm (0.6 inches)	65%	extreme
September Weather	29°C (84°F)	97 mm (3.8 inches)	73%	extreme
October Weather	25°C (77°F)	37 mm (1.5 inches)	76%	very high
November Weather	20°C (69°F)	37 mm (1.5 inches)	80%	high
December Weather	17°C (64°F)	20 mm (0.8 inches)	86%	high