Month guide · Rio Maior, Portugal
Rio Maior in December: weather and what to expect
In December, Rio Maior averages highs of 15°C and lows of 8°C, with about 10 rainy days and 83 mm of rain. Highs are 2°C cooler than in November and 1°C warmer than in January. Crowds in Oeste e Vale do Tejo are low.
Is December a good time to visit?
Good for
No verdicts for Rio Maior in December yet. They only use climate values that are precise enough to judge with.
Not ideal for
- Reliable dry weatherAbout 10 rainy days in the month
Daily highs through December
Town-level · ERA5-Land 1991-2020Highs fall about 1°C over the month.
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 Rio Maior |
|---|---|---|---|
| Aljezur, Algarve | 16°C | 10 | 225 km |
| São Marcos da Serra, Algarve | 16°C | 9 | 225 km |
| Odemira, Alentejo | 16°C | 9 | 195 km |
| Mértola, Alentejo | 16°C | 7 | 219 km |
| Vila Nova de Milfontes, Alentejo | 16°C | 10 | 180 km |
The nearest towns with a warmer December. Distances are in a straight line.
How December is changing
Town-level · ERA5-LandDecember highs are 0.7°C warmer than in 1991-2000, and December rainfall is down about 25% (2016-2025 against 1991-2000).
Questions about Rio Maior in December
Is December a good time to visit Rio Maior?
It is less suited to reliable dry weather (about 10 rainy days in the month).
How warm is Rio Maior in December?
Average highs are 15°C and lows 8°C. November averages 17°C and January 14°C.
Does it rain much in Rio Maior in December?
About 10 days have at least 1 mm of rain, with 83 mm in total over the month.
Is Rio Maior busy in December?
In December 2025, nights booked through online platforms in Oeste e Vale do Tejo 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 Rio Maior in December?
About 9 h 25 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