September Weather in Santiago, Brazil

Last updated: August 22, 2025

In September, the average temperature in Santiago, Brazil hovers around 18°C (64°F). Expect a minimum temperature of 5°C (41°F) and a maximum that can reach up to 33°C (91°F). The region typically experiences 150 mm (5.9 in) of precipitation over 11 days, contributing to an average humidity of 74%.

September Temperature in Santiago

In September in Santiago, the average temperature is 18°C (64°F). The maximum can reach 33°C (91°F) and the minimum can be as low as 5°C (41°F). This delightful range makes it a perfect time for travelers to enjoy outdoor activities while also being prepared for cooler evenings.

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

The chart illustrates September temperature patterns in Santiago, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Santiago, September typically has an average temperature of 18°C (64°F), with highs reaching up to 33°C (91°F) and lows dropping to around 5°C (41°F).

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

September Precipitation in Santiago

In Santiago in September, the total precipitation amount reaches 150 mm (5.9 in) over the course of 11 days.

September Precipitation Trends in Santiago

The chart displays monthly precipitation patterns in Santiago, 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 Santiago, September typically receives around 150 mm (5.9 inches) of precipitation spread over approximately 11 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 Santiago

In Santiago in September humidity is 74%. With an average temperature of 18°C (64°F), this humidity feels like a warm embrace, making it ideal for leisurely strolls but potentially uncomfortable for extended outdoor activities.

September Average Humidity in Santiago

This chart illustrates the average monthly humidity levels in Santiago, 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 Santiago is approximately 74%, 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 Santiago

In Santiago in September, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in Santiago.

Maximum UV Index Levels in Santiago for September

The chart shows the monthly maximum UV Index (UVI) for Santiago 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 Santiago typically reaches 10, which falls under the very high exposure category.

Data source: Santiago 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 Santiago Compares to Other Months

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

This table compares monthly weather conditions in Santiago, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	25°C (77°F)	176 mm (6.9 inches)	74%	extreme
February Weather	24°C (75°F)	101 mm (4.0 inches)	73%	extreme
March Weather	22°C (73°F)	146 mm (5.7 inches)	73%	extreme
April Weather	20°C (68°F)	104 mm (4.1 inches)	81%	very high
May Weather	16°C (61°F)	195 mm (7.7 inches)	87%	high
June Weather	15°C (59°F)	113 mm (4.4 inches)	84%	moderate
July Weather	14°C (57°F)	103 mm (4.1 inches)	80%	moderate
August Weather	15°C (60°F)	116 mm (4.6 inches)	71%	high
September Weather	18°C (64°F)	150 mm (5.9 inches)	74%	very high
October Weather	20°C (68°F)	174 mm (6.9 inches)	77%	extreme
November Weather	22°C (72°F)	143 mm (5.6 inches)	77%	extreme
December Weather	24°C (75°F)	89 mm (3.5 inches)	85%	extreme