The territory of Portugal includes an area in the Iberian Peninsula (referred to as the continent by most Portuguese) and two archipelagos in the Atlantic Ocean: the archipelagos of Madeira and the Azores. It lies between latitudes 32° and 43° N, and longitudes 32° and 6° W.
Mainland Portugal is split by its main river, the Tagus that flows from Spain and disgorges in Tagus Estuary, in Lisbon, before escaping into the Atlantic. The northern landscape is mountainous towards the interior with several plateaus indented by river valleys, whereas the south, that includes the Algarve and the Alentejo regions, is characterized by rolling plains.
Portugal's highest peak is the similarly named Mount Pico on the island of Pico in the Azores. This ancient volcano, which measures 2,351 m (7,713 ft) is an iconic symbol of the Azores, while the Serra da Estrela on the mainland (the summit being 1,991 m (6,532 ft) above sea level) is an important seasonal attraction for skiers and winter sports enthusiasts.
The archipelagos of Madeira and the Azores are scattered within the Atlantic Ocean: the Azores straddling the Mid-Atlantic Ridge on a tectonic triple junction, and Madeira along a range formed by in-plate hotspot geology. Geologically, these islands were formed by volcanic and seismic events. The last terrestrial volcanic eruption occurred in 1957–58 (Capelinhos) and minor earthquakes occur sporadically, usually of low intensity.
Portugal's exclusive economic zone, a sea zone over which the Portuguese have special rights over the exploration and use of marine resources, has 1,727,408 km2. This is the 3rd largest exclusive economic zone of the European Union and the 11th largest in the world.
Portugal is defined as a Mediterranean climate (Csa in the South, interior, and Douro region; Csb in the North, Central Portugal and coastal Alentejo; mixed oceanic climate along the northern half of the coastline and also Semi-arid climate or Steppe climate (BSk in certain parts of Beja district far South) according to the Köppen-Geiger Climate Classification), and is one of the warmest European countries: the annual average temperature in mainland Portugal varies from 8–12 °C (46.4–53.6 °F) in the mountainous interior north to 16–18 °C (60.8–64.4 °F) in the south and on the Guadiana river basin. There are however, variations from the highlands to the lowlands: Rivas Martinez, presents several different bioclimatic zones for Portugal. The Algarve, separated from the Alentejo region by mountains reaching up to 900 metres (3,000 ft) in Alto de Fóia, has a climate similar to that of the southern coastal areas of Spain or Southwest Australia.
Annual average rainfall in the mainland varies from just over 3,200 mm (126.0 in) in the northern mountains to less than 300 mm (11.8 in) in the area of the Massueime River, near Côa, along the Douro river. Mount Pico is recognized as receiving the largest annual rainfall (over 6,250 mm (246.1 in) per year) in Portugal, according to Instituto Português do Mar e da Atmosfera (English: Portuguese Institute of the Sea and the Atmosphere).
In some areas, such as the Guadiana basin, annual average temperatures can be as high as 28 °C (82 °F), and summer highest temperatures routinely are over 40 °C (104 °F). The record high of 47.4 °C (117.3 °F) was recorded in Amareleja, although this might not be the hottest spot in summer, according to satellite readings.
Snowfalls occur regularly in the winter in the interior North and Centre of the country in districts such as Guarda, Bragança, Viseu and Vila Real, particularly on the mountains. In winter temperatures may drop below −10.0 °C (14.0 °F) in particular in Serra da Estrela, Serra do Gerês, Serra do Marão and Serra de Montesinho. In these places snow can fall any time from October to May. In the South of the country snowfalls are rare but still occur in the highest elevations. While the official absolute minimum by IPMA is −16.0 °C (3.2 °F) in Penhas da Saúde and Miranda do Douro, lower temperatures have been recorded, such as −17.5 °C (0.5 °F) by Bragança Polytechnic Institute in the outskirts of the city in 1983, and below −20.0 °C (−4.0 °F) in Serra da Estrela.
Portugal has around 2500 to 3200 hours of sunshine a year, an average of 4–6 h in winter and 10–12 h in the summer, with higher values in the south-east and lower in the north-west.
The sea surface temperature on the west coast of mainland Portugal varies from 13–15 °C (55.4–59.0 °F) in winter to 18–22 °C (64.4–71.6 °F) in the summer while on the south coast it ranges from 15 °C (59.0 °F) in winter and rises in the summer to about 23 °C (73.4 °F) occasionally reaching 26 °C (78.8 °F).
Both the archipelagos of the Azores and Madeira have a subtropical climate, although variations between islands exist, making weather predictions very difficult (owing to rough topography). The Madeira and Azorean archipelagos have a narrower temperature range, with annual average temperatures exceeding 20 °C (68 °F) along the coast (according to the Portuguese Meteorological Institute). Some islands in Azores do have drier months in the summer. Consequently, the island of the Azores have been identified as having a Mediterranean climate (both Csa and Csb types), while some islands (such as Flores or Corvo) are classified as Maritime Temperate (Cfb) and Humid subtropical (Cfa), respectively, according to Köppen-Geiger classification.
Porto Santo island in Madeira has a semi-arid steppe climate (BSh). The Savage Islands, which are part of the regional territory of Madeira and a nature reserve are unique in being classified as a desert climate (BWh) with an annual average rainfall of approximately 150 mm (5.9 in). The sea surface temperature in the archipelagos varies from 17–18 °C (62.6–64.4 °F) in winter to 24–25 °C (75.2–77.0 °F) in the summer occasionally reaching 25 °C (77.0 °F).
Despite the fact that humans have occupied the territory of Portugal for thousands of years, something still remains of the original vegetation. In Gerês both mature deciduous and coniferous forests can be found, an extremely rare worldwide mature Mediterranean forest remain in some parts of the Arrábida mountain and a subtropical laurissilva forest, dating back to the Tertiary period, covers its largest continuous area in the world in the Madeira main island. Due to the human population decrease and rural exodus, Pyrenean oak and other local native trees are colonizing many abandoned areas.
Boar, Iberian red deer, roe deer, and the Iberian wild goat, are reported to have expanded greatly during recent decades. Boars were found recently roaming at night inside large urban areas, like in Setubal. Protected areas of Portugal include one national park (Portuguese: Parque Nacional), 12 natural parks (Portuguese: Parque Natural), nine natural reserves (Portuguese: Reserva Natural), five natural monuments (Portuguese: Monumento Natural), and seven protected landscapes (Portuguese: Paisagem Protegida), which include the Parque Nacional da Peneda-Gerês, the Parque Natural da Serra da Estrela and the Paul d'Arzila.
These natural environments are shaped by diverse flora, and include widespread species of pine (especially the Pinus pinaster and Pinus pinea species), the English oak (Quercus robur), the Pyrenean oak (Quercus pyrenaica) the chestnut (Castanea sativa), the cork-oak (Quercus suber), the holm oak (Quercus ilex) or the Portuguese oak (Quercus faginea). Due to their economic value, some species of the Eucalyptus genus were introduced and are now common, despite their environmental impact.
Laurisilva is a unique type of subtropical rainforest found in few areas of Europe and the world: in the Azores, and in particular on the island of Madeira, there are large forests of endemic Laurisilva forests (the latter protected as a natural heritage preserve). There are several species of diverse mammalian fauna, including the fox, badger, iberian lynx, iberian wolf, wild goat (Capra pyrenaica), wild cat (Felis silvestris), hare, weasel, polecat, chameleon, mongoose, civet, brown bear (spotted near Rio Minho, close to Peneda-Gerês) and many others. Portugal is an important stopover for migratory birds, in places such as Cape St. Vincent or the Monchique mountains, where thousands of birds cross from Europe to Africa during the autumn or in the spring (return migration).
Most of the avian species congregate along the Iberian Peninsula since it is the closest stopover between Northern Europe and Africa. Six hundred bird species occur in Portugal (either for nesting or during the course of migration), and annually there are new registries of nesting species. The archipelagos of the Azores and Madeira are transient stopover for American, European, and African birds, while continental Portugal mostly encounters European and African bird species.
There are more than 100 freshwater fish species, varying from the giant European catfish (in the Tagus International Natural Park) to some small and endemic species that live only in small lakes (along the western portion of country, for example). Some of these rare and specific species are highly endangered because of habitat loss, pollution and drought. Up-welling along the west coast of Portugal makes the sea extremely rich in nutrients and diverse species of marine fish; the Portuguese marine waters are one of the richest in the world. Marine fish species are more common, and include thousands of species, such as the sardine (Sardina pilchardus), tuna and Atlantic mackerel. Bioluminescent species are also well represented (including species in different colour spectrum and forms), like the glowing plankton that are possible to observe in some beaches.
There are many endemic insect species, most only found in certain parts of Portugal, while other species are more widespread like the stag beetle (Lucanus cervus) and the cicada. The Macaronesian islands (Azores and Madeira) have many endemic species (like birds, reptiles, bats, insects, snails and slugs) that evolved independently from other regions of Portugal. In Madeira, for example, it is possible to observe more than 250 species of land gastropods.