December Weather in Sao Martinho do Porto, Portugal

Last updated: August 27, 2025

In Sao Martinho do Porto, Portugal, the average temperature in December hovers around 13°C (56°F), offering a mild climate. Expect minimums of 7°C (45°F) and maximums reaching 18°C (65°F). Precipitation levels average 73 mm (2.9 in) across 11 days, contributing to an average humidity of 85%, which adds a refreshing touch to the air.

December Temperature in Sao Martinho do Porto

In December in Sao Martinho do Porto, the average temperature is 13°C (56°F). Maximums can reach 18°C (65°F), while minimums can be as low as 7°C (45°F). This climate makes it a pleasant destination for travelers looking to enjoy mild weather and comfortable outdoor activities.

December Weather in Sao Martinho do Porto: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in Sao Martinho do Porto, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Sao Martinho do Porto, December typically has an average temperature of 13°C (56°F), with highs reaching up to 18°C (65°F) and lows dropping to around 7°C (45°F).

Data source: Temperature data for Sao Martinho do Porto generated using information from the Copernicus Climate Change Service.

December Precipitation in Sao Martinho do Porto

In Sao Martinho do Porto in December, the precipitation amount is 73 mm (2.9 in), spread over 11 days.

December Precipitation Trends in Sao Martinho do Porto

The chart displays monthly precipitation patterns in Sao Martinho do Porto, with values for each month alongside December’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how December’s conditions compare to those of other months. In Sao Martinho do Porto, December typically receives around 73 mm (2.9 inches) of precipitation spread over approximately 11 days.

Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

December Humidity in Sao Martinho do Porto

In Sao Martinho do Porto in December humidity is 85%. With an average temperature of 13°C (56°F), this humidity feels like a damp chill that wraps around you, making outdoor activities feel heavier and less enjoyable, as layers of clothing cling to the skin and breath becomes visible in the moist air.

December Average Humidity in Sao Martinho do Porto

This chart illustrates the average monthly humidity levels in Sao Martinho do Porto, with December’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In December, average humidity in Sao Martinho do Porto is approximately 85%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Sao Martinho do Porto

In Sao Martinho do Porto in December, the maximum UV index is 3, which corresponds to a moderate Exposure Category. The time to burn is approximately 30 minutes. For more details on the hourly UV index in Sao Martinho do Porto, you can check the information here.

Maximum UV Index Levels in Sao Martinho do Porto for December

The chart shows the monthly maximum UV Index (UVI) for Sao Martinho do Porto in December, 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 December, the maximum UV index in Sao Martinho do Porto typically reaches 3, which falls under the moderate exposure category.

Data source: Sao Martinho do Porto December 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 December Weather in Sao Martinho do Porto Compares to Other Months

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

This table compares monthly weather conditions in Sao Martinho do Porto, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	12°C (54°F)	50 mm (2.0 inches)	85%	moderate
February Weather	13°C (56°F)	55 mm (2.1 inches)	75%	moderate
March Weather	13°C (57°F)	73 mm (2.9 inches)	72%	high
April Weather	15°C (59°F)	80 mm (3.1 inches)	70%	very high
May Weather	17°C (63°F)	39 mm (1.5 inches)	70%	very high
June Weather	18°C (65°F)	24 mm (1.0 inches)	63%	extreme
July Weather	19°C (67°F)	12 mm (0.5 inches)	60%	very high
August Weather	20°C (68°F)	7 mm (0.3 inches)	60%	very high
September Weather	19°C (67°F)	24 mm (1.0 inches)	67%	very high
October Weather	18°C (64°F)	69 mm (2.7 inches)	74%	high
November Weather	15°C (59°F)	91 mm (3.6 inches)	83%	moderate
December Weather	13°C (56°F)	73 mm (2.9 inches)	85%	moderate