September Weather in Rio Branco, Brazil

Last updated: August 22, 2025

In September, the average temperature in Rio Branco, Brazil is a warm 27°C (82°F). Expect a minimum of 15°C (60°F) and whopping highs of 38°C (100°F). With 53 mm (2.1 in) of precipitation falling over 10 days, it's wise to prepare for brief showers. The average humidity stands at a comfortable 33%, ensuring a pleasant atmosphere for your adventures.

September Temperature in Rio Branco

In September in Rio Branco, the average temperature is 27°C (82°F), with maximums that can reach 38°C (100°F) and minimums that can dip as low as 15°C (60°F). This pleasant climate makes it an ideal destination for travelers seeking warmth and variety in their outdoor activities.

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

The chart illustrates September temperature patterns in Rio Branco, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Rio Branco, September typically has an average temperature of 27°C (82°F), with highs reaching up to 38°C (100°F) and lows dropping to around 15°C (60°F).

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

September Precipitation in Rio Branco

In Rio Branco in September, the precipitation amount is 53 mm (2.1 in) spread over a duration of 10 days.

September Precipitation Trends in Rio Branco

The chart displays monthly precipitation patterns in Rio Branco, 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 Branco, September typically receives around 53 mm (2.1 inches) of precipitation spread over approximately 10 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 Branco

In Rio Branco in September humidity is 33%. With an average temperature of 27°C (82°F), this humidity feels like a warm, gentle breeze that makes exploring the sights enjoyable but requires some hydration breaks to stay refreshed.

September Average Humidity in Rio Branco

This chart illustrates the average monthly humidity levels in Rio Branco, 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 Branco is approximately 33%, 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 Branco

In Rio Branco in September, the maximum UV index is 12, which corresponds to an extreme Exposure Category. The time to burn is just 10 minutes, underscoring the importance of sun protection. For detailed information, you can check the Hourly UV Index in Rio Branco.

Maximum UV Index Levels in Rio Branco for September

The chart shows the monthly maximum UV Index (UVI) for Rio Branco 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 Branco typically reaches 12, which falls under the extreme exposure category.

Data source: Rio Branco 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 Branco Compares to Other Months

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

This table compares monthly weather conditions in Rio Branco, 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)	264 mm (10.4 inches)	88%	extreme
February Weather	25°C (78°F)	285 mm (11.2 inches)	87%	extreme
March Weather	26°C (78°F)	288 mm (11.3 inches)	87%	extreme
April Weather	26°C (78°F)	168 mm (6.6 inches)	89%	extreme
May Weather	25°C (77°F)	83 mm (3.3 inches)	84%	extreme
June Weather	24°C (76°F)	33 mm (1.3 inches)	67%	very high
July Weather	25°C (76°F)	14 mm (0.6 inches)	46%	very high
August Weather	26°C (79°F)	26 mm (1.0 inches)	37%	extreme
September Weather	27°C (82°F)	53 mm (2.1 inches)	33%	extreme
October Weather	27°C (81°F)	125 mm (4.9 inches)	44%	extreme
November Weather	26°C (80°F)	206 mm (8.1 inches)	73%	extreme
December Weather	26°C (79°F)	305 mm (12.0 inches)	88%	extreme