December Weather in Sines, Portugal

Last updated: August 27, 2025

In December, the average temperature in Sines, Portugal is a mild 13°C (55°F), with minimums dropping to 4°C (40°F) and maximums reaching 20°C (69°F). Expect around 52 mm (2.0 in) of precipitation spread over 8 days, and an average humidity of 81%. Enjoy the pleasant yet variable weather!

December Temperature in Sines

In December in Sines, the average temperature is 13°C (55°F). Maximums can reach 20°C (69°F), while minimums can dip as low as 4°C (40°F). This mild climate makes Sines an ideal destination for outdoor activities and sightseeing during this time of year.

December Weather in Sines: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in Sines, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Sines, December typically has an average temperature of 13°C (55°F), with highs reaching up to 20°C (69°F) and lows dropping to around 4°C (40°F).

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

December Precipitation in Sines

In Sines in December, the total precipitation amount is 52 mm (2.0 in) recorded over a span of 8 days.

December Precipitation Trends in Sines

The chart displays monthly precipitation patterns in Sines, 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 Sines, December typically receives around 52 mm (2.0 inches) of precipitation spread over approximately 8 days.

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

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Millimeters (mm) Inches (in)

December Humidity in Sines

In Sines in December, humidity is 81%. With an average temperature of 13°C (55°F), this humidity feels like a damp blanket wrapping around you, making strolls outdoors feel heavy and slightly oppressive, which may be less than ideal for travelers looking to explore comfortably.

December Average Humidity in Sines

This chart illustrates the average monthly humidity levels in Sines, 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 Sines is approximately 81%, 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 Sines

In Sines 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 Sines, you can check the information here.

Maximum UV Index Levels in Sines for December

The chart shows the monthly maximum UV Index (UVI) for Sines 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 Sines typically reaches 3, which falls under the moderate exposure category.

Data source: Sines 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 Sines Compares to Other Months

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

This table compares monthly weather conditions in Sines, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	11°C (52°F)	31 mm (1.2 inches)	80%	moderate
February Weather	13°C (55°F)	55 mm (2.2 inches)	73%	moderate
March Weather	14°C (57°F)	82 mm (3.2 inches)	71%	high
April Weather	15°C (59°F)	70 mm (2.7 inches)	69%	very high
May Weather	18°C (65°F)	27 mm (1.1 inches)	69%	very high
June Weather	19°C (67°F)	9 mm (0.4 inches)	67%	extreme
July Weather	21°C (70°F)	3 mm (0.1 inches)	69%	very high
August Weather	21°C (71°F)	2 mm (0.1 inches)	68%	very high
September Weather	21°C (70°F)	13 mm (0.5 inches)	71%	very high
October Weather	18°C (65°F)	45 mm (1.8 inches)	75%	high
November Weather	15°C (59°F)	62 mm (2.4 inches)	78%	moderate
December Weather	13°C (55°F)	52 mm (2.0 inches)	81%	moderate