Portugal: Geography and climate

For such a small country, Portugal produces a remarkable diversity of wines. Roughly rectangular in shape, it is under 600 km/360 miles long and no more than 200 km wide. The wines produced on the flat coastal littoral are strongly influenced by prevailing Atlantic westerly winds. Rainfall, which reaches 2,000 mm/78 in a year on the mountain ranges north of Oporto, diminishes sharply to less than 500 mm in some inland wine areas. The temperate maritime climate, with warm summers and cool, wet winters, becomes more extreme towards the south and east. An average annual temperature of around 10 °C/50 °F in the northern hills compares with more than 17.5 °C on the southern plains, where, in summer, temperatures frequently exceed 35 °C/95 °F.