Climatology
This page presents Portugal's climate context for the current climatology, 1991-2020, derived from observed, historical data. Information should be used to build a strong understanding of current climate conditions in order to appreciate future climate scenarios and projected change. You can visualize data for the current climatology through spatial variation, the seasonal cycle, or as a time series. Analysis is available for both annual and seasonal data. Data presentation defaults to national-scale aggregation, however sub-national data aggregations can be accessed by clicking within a country, on a sub-national unit. Other historical climatologies can be selected from the Time Period dropdown list.
Observed, historical data is produced by the Climatic Research Unit (CRU) of University of East Anglia. Data is presented at a 0.5º x 0.5º (50km x 50km) resolution.
The climate in mainland Portugal is predominantly influenced by latitude, orography and its proximity to the Atlantic Ocean. Climate variables, such as precipitation and temperature, display strong north-south and west-east gradients as well as a very sharp seasonal and inter-annual variability. Average annual precipitation in mainland Portugal shows a strong spatial variability, with the highest values observed in the mountainous regions of Minho, exceeding 2,500 mm, and the lowest values, below 600 mm, in some northern and central inland regions (non-mountainous areas) and in inland Alentejo. On average, around 40% of annual precipitation occurs during winter (December to February) and only 7% of total annual precipitation occurs during summer (June to August). Transition seasons – spring (March to May) and autumn (September to November) – show a very variable inter-annual distribution, with approximately 24% and 28% of total average precipitation during these seasons, respectively. Average annual temperature is between 6°C and 9°C in inland North and Centre and higher, above 17°C in eastern Algarve and the Guadiana valley.