December Weather in Mertola, Portugal

Last updated: August 27, 2025

In December, the average temperature in Mertola, Portugal is a mild 11°C (53°F), with minimums dipping to -1°C (30°F) and maximums climbing to 21°C (70°F). Expect about 40 mm (1.6 in) of precipitation over 5 days, and humidity levels will hover around a comfortable 81%. Prepare for a mix of weather as you explore this vibrant location!

December Temperature in Mertola

In December in Mertola, the average temperature is 11°C (53°F). Maximum temperatures can reach 21°C (70°F), while minima can drop to as low as -1°C (30°F). It's advisable to pack layers to prepare for both warm afternoons and chilly evenings during your travels.

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

The chart illustrates December temperature patterns in Mertola, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Mertola, December typically has an average temperature of 11°C (53°F), with highs reaching up to 21°C (70°F) and lows dropping to around -1°C (30°F).

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

December Precipitation in Mertola

In Mertola in December, the precipitation amount is 40 mm (1.6 in) over the course of 5 days.

December Precipitation Trends in Mertola

The chart displays monthly precipitation patterns in Mertola, 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 Mertola, December typically receives around 40 mm (1.6 inches) of precipitation spread over approximately 5 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 Mertola

In Mertola in December, humidity is 81%. With an average temperature of 11°C (53°F), this humidity feels like a damp chill that can make outdoor activities uncomfortable, requiring layers for protection against the moisture in the air while exploring.

December Average Humidity in Mertola

This chart illustrates the average monthly humidity levels in Mertola, 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 Mertola 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 Mertola

In Mertola 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 Mertola, you can check the information here.

Maximum UV Index Levels in Mertola for December

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

Data source: Mertola 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 Mertola Compares to Other Months

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

This table compares monthly weather conditions in Mertola, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	9°C (49°F)	23 mm (0.9 inches)	80%	moderate
February Weather	12°C (54°F)	37 mm (1.5 inches)	73%	moderate
March Weather	13°C (56°F)	67 mm (2.7 inches)	71%	high
April Weather	15°C (60°F)	55 mm (2.2 inches)	69%	very high
May Weather	20°C (68°F)	26 mm (1.0 inches)	69%	very high
June Weather	22°C (72°F)	9 mm (0.4 inches)	67%	extreme
July Weather	24°C (76°F)	2 mm (0.1 inches)	69%	extreme
August Weather	26°C (78°F)	2 mm (0.1 inches)	68%	very high
September Weather	23°C (74°F)	22 mm (0.8 inches)	71%	very high
October Weather	19°C (67°F)	38 mm (1.5 inches)	75%	high
November Weather	14°C (57°F)	48 mm (1.9 inches)	78%	moderate
December Weather	11°C (53°F)	40 mm (1.6 inches)	81%	moderate