September Weather in Alter do Chao, Portugal

Last updated: August 27, 2025

In Alter do Chao, Portugal, the average temperature in September is a pleasant 22°C (73°F). Expect a range from a refreshing 9°C (49°F) at its coolest to a warm 37°C (99°F) at its peak. During this month, anticipate 29 mm (1.1 in) of precipitation spread over about 3 days, with an average humidity of 67%. Enjoy the diverse climate that September brings!

September Temperature in Alter do Chao

In September in Alter do Chao, the average temperature is 22°C (73°F), with maximums reaching up to 37°C (99°F) and minimums dropping as low as 9°C (49°F). This diverse temperature range makes Alter do Chao an ideal destination for travelers looking to experience both warm and cool conditions.

September Weather in Alter do Chao: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Alter do Chao, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Alter do Chao, September typically has an average temperature of 22°C (73°F), with highs reaching up to 37°C (99°F) and lows dropping to around 9°C (49°F).

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

September Precipitation in Alter do Chao

In Alter do Chao in September, the precipitation amount is 29 mm (1.1 in) over the course of 3 days.

September Precipitation Trends in Alter do Chao

The chart displays monthly precipitation patterns in Alter do Chao, 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 Alter do Chao, September typically receives around 29 mm (1.1 inches) of precipitation spread over approximately 3 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 Alter do Chao

In Alter do Chao in September, humidity is 67%. With an average temperature of 22°C (73°F), this humidity feels like a warm, damp blanket enveloping you, making outdoor activities slightly uncomfortable but still bearable for travelers who enjoy a tropical atmosphere.

September Average Humidity in Alter do Chao

This chart illustrates the average monthly humidity levels in Alter do Chao, 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 Alter do Chao is approximately 67%, 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 Alter do Chao

In Alter do Chao 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 Alter do Chao.

Maximum UV Index Levels in Alter do Chao for September

The chart shows the monthly maximum UV Index (UVI) for Alter do Chao 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 Alter do Chao typically reaches 8, which falls under the very high exposure category.

Data source: Alter do Chao 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 Alter do Chao Compares to Other Months

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

This table compares monthly weather conditions in Alter do Chao, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	9°C (48°F)	40 mm (1.6 inches)	85%	moderate
February Weather	11°C (53°F)	52 mm (2.0 inches)	75%	moderate
March Weather	13°C (55°F)	92 mm (3.6 inches)	72%	high
April Weather	15°C (59°F)	84 mm (3.3 inches)	70%	very high
May Weather	19°C (66°F)	37 mm (1.4 inches)	70%	very high
June Weather	21°C (70°F)	14 mm (0.6 inches)	63%	extreme
July Weather	24°C (75°F)	4 mm (0.2 inches)	60%	very high
August Weather	24°C (76°F)	5 mm (0.2 inches)	60%	very high
September Weather	22°C (73°F)	29 mm (1.1 inches)	67%	very high
October Weather	18°C (65°F)	52 mm (2.1 inches)	74%	high
November Weather	13°C (55°F)	80 mm (3.2 inches)	83%	moderate
December Weather	11°C (52°F)	73 mm (2.9 inches)	85%	moderate