September Weather in Santo Tirso, Portugal

Last updated: August 27, 2025

In September, the average temperature in Santo Tirso, Portugal hovers around 20°C (68°F). Expect a minimum of 10°C (51°F) and a maximum of 34°C (94°F), making it a month of pleasant warmth. With an average precipitation of 39 mm (1.5 in) spread over 6 days, you might want to keep an umbrella handy. The average humidity sits at a comfortable 71%, ensuring a refreshing atmosphere.

September Temperature in Santo Tirso

In September in Santo Tirso, the average temperature is 20°C (68°F). Maximums can reach 34°C (94°F), while minimums can drop to as low as 10°C (51°F). This pleasant climate makes it an ideal time for outdoor adventures and sightseeing.

September Weather in Santo Tirso: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Santo Tirso, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Santo Tirso, September typically has an average temperature of 20°C (68°F), with highs reaching up to 34°C (94°F) and lows dropping to around 10°C (51°F).

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

September Precipitation in Santo Tirso

In Santo Tirso in September, the precipitation amount is 39 mm (1.5 in), occurring over the course of 6 days.

September Precipitation Trends in Santo Tirso

The chart displays monthly precipitation patterns in Santo Tirso, 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 Santo Tirso, September typically receives around 39 mm (1.5 inches) of precipitation spread over approximately 6 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 Santo Tirso

In Santo Tirso in September, humidity is 71%. With an average temperature of 20°C (68°F), this humidity feels like a warm, moist embrace that can quickly lead to discomfort for travelers. The air clings to your skin, making even short walks feel more strenuous, while reaching for a refreshing drink becomes essential to stay hydrated.

September Average Humidity in Santo Tirso

This chart illustrates the average monthly humidity levels in Santo Tirso, 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 Santo Tirso is approximately 71%, 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 Santo Tirso

In Santo Tirso 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 Santo Tirso.

Maximum UV Index Levels in Santo Tirso for September

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

Data source: Santo Tirso 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 Santo Tirso Compares to Other Months

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

This table compares monthly weather conditions in Santo Tirso, 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 (49°F)	91 mm (3.6 inches)	87%	low
February Weather	11°C (52°F)	138 mm (5.4 inches)	81%	moderate
March Weather	12°C (54°F)	141 mm (5.6 inches)	78%	high
April Weather	14°C (58°F)	146 mm (5.7 inches)	79%	very high
May Weather	17°C (63°F)	81 mm (3.2 inches)	78%	very high
June Weather	18°C (66°F)	50 mm (2.0 inches)	71%	extreme
July Weather	21°C (70°F)	23 mm (0.9 inches)	63%	very high
August Weather	21°C (70°F)	19 mm (0.7 inches)	64%	very high
September Weather	20°C (68°F)	39 mm (1.5 inches)	71%	very high
October Weather	17°C (62°F)	121 mm (4.8 inches)	79%	high
November Weather	13°C (55°F)	156 mm (6.1 inches)	86%	moderate
December Weather	11°C (52°F)	187 mm (7.4 inches)	87%	low