Month guide · Rio Maior, Portugal
Rio Maior in May: weather and what to expect
In May, Rio Maior averages highs of 22°C and lows of 13°C, with about 9 rainy days and 59 mm of rain. Highs are 3°C warmer than in April and 3°C cooler than in June. Crowds in the Alentejo are low.
Is May a good time to visit?
Good for
No verdicts for Rio Maior in May 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 May
Town-level · ERA5-Land 1991-2020Highs climb about 4°C over the month.
May in detail
Town-level · ERA5-LandCrowds, holidays and daylight
Public holidays in May 2027
- 1 May Labor Day
- 27 May Corpus Christi
Local (municipal) holidays are not included.
Warmer in May
Where is warm in May →| Place | High | Rain days | From Rio Maior |
|---|---|---|---|
| Almeirim, Alentejo | 24°C | 8 | 30 km |
| Bemfica, Alentejo | 24°C | 8 | 31 km |
| São Vicente do Paul, Alentejo | 23°C | 8 | 27 km |
| Vale de Santarém, Alentejo | 23°C | 8 | 24 km |
| Alpiarça, Alentejo | 23°C | 8 | 32 km |
The nearest towns with a warmer May. Distances are in a straight line.
How May is changing
Town-level · ERA5-LandMay highs are 1.4°C warmer than in 1991-2000, and May rainfall is down about 40% (2016-2025 against 1991-2000). Days above 25°C in May went from 4.5 to 7.9 a year on average.
Questions about Rio Maior in May
How warm is Rio Maior in May?
Average highs are 22°C and lows 13°C. April averages 19°C and June 25°C.
Does it rain much in Rio Maior in May?
About 9 days have at least 1 mm of rain, with 59 mm in total over the month.
Is Rio Maior busy in May?
In May 2025, nights booked through online platforms in the Alentejo were about 30% 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 May?
About 14 h 18 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