Month guide · Mértola, Portugal
Mértola in December: weather and what to expect
In December, Mértola averages highs of 16°C and lows of 8°C, with about 7 rainy days and 60 mm of rain. Highs are 3°C cooler than in November and 1°C warmer than in January. Crowds in the Alentejo are low.
Is December a good time to visit?
Good for
No verdicts for Mértola in December yet. They only use climate values that are precise enough to judge with.
Not ideal for
Nothing stands out as a weaker fit.
Daily highs through December
Town-level · ERA5-Land 1991-2020Highs fall about 1°C over the month. A day above 20°C happens in roughly 1 December in 3.
December in detail
Town-level · ERA5-LandCrowds, holidays and daylight
Public holidays in December 2026
- 1 Dec Restoration of Independence Day
- 8 Dec Immaculate Conception
- 25 Dec Christmas Day
Local (municipal) holidays are not included.
Warmer in December
Where is warm in December →| Place | High | Rain days | From Mértola |
|---|---|---|---|
| Castro Marim, Algarve | 16°C | 7 | 51 km |
| Vila Real de Santo António, Algarve | 16°C | 7 | 54 km |
| Conceição, Algarve | 16°C | 7 | 55 km |
| Altura, Algarve | 16°C | 7 | 54 km |
| Monte Gordo, Algarve | 16°C | 7 | 54 km |
The nearest towns with a warmer December. Distances are in a straight line.
How December is changing
Town-level · ERA5-LandDecember highs are 0.9°C warmer than in 1991-2000, and December rainfall is down about 35% (2016-2025 against 1991-2000). Days above 20°C in December went from 0.6 to 2.4 a year on average.
Questions about Mértola in December
How warm is Mértola in December?
Average highs are 16°C and lows 8°C. November averages 19°C and January 15°C.
Does it rain much in Mértola in December?
About 7 days have at least 1 mm of rain, with 60 mm in total over the month.
Is Mértola busy in December?
In December 2025, nights booked through online platforms in the Alentejo were about 15% of the busiest month, which we count as low. The figure is for the whole region and leaves out hotels.
How long are the days in Mértola in December?
About 9 h 35 min from sunrise to sunset in the middle of the month.
Sources
Climate: ERA5-Land, Copernicus Climate Change Service (C3S) Climate Data Store, contains modified Copernicus information (CC BY 4.0). Crowds: Eurostat, nights spent in short-stay accommodation booked through online platforms (tour_ce_omn12) (CC BY 4.0). Place names and populations: GeoNames (CC BY 4.0). Climate averages cover 1991-2020. Daylight: calculated from the town's coordinates. Full methodology