Portugal has a Mediterranean climate with warm, dry summers and mild, wet winters. It’s one of the warmest countries in Europe, but conditions vary dramatically depending on whether you’re in the green, rainy north or the sun-baked south. The national average rainfall is about 787 mm per year, but that number hides a huge range, from nearly 2,000 mm in parts of the northwest to just 411 mm in the southern Algarve.
Two Climate Zones, One Small Country
Portugal fits into two categories on the Köppen-Geiger climate classification. The southern half and much of the interior fall under a hot-summer Mediterranean climate, with summer highs regularly topping 28°C (83°F). The northern half and the Atlantic-facing coast have a warm-summer Mediterranean climate, where summers stay cooler and rain is more frequent year-round.
The dividing line roughly follows the Tagus River, which cuts across the country through Lisbon. South of it, the landscape turns drier and more arid. North of it, the hills get greener, the rivers fuller, and the skies cloudier. This north-south split is the single most important thing to understand about Portugal’s weather.
Temperatures by Region
Lisbon and Faro, in the center and south, share similar summer peaks: August highs average around 28°C (83°F). Winters are mild in both cities, with daytime highs near 16°C in January and February. Overnight lows dip to about 8°C (47°F) but rarely feel harsh. Faro edges slightly warmer in winter and stays more comfortable at night in summer, with lows around 20°C compared to Lisbon’s 18°C, thanks to the Algarve’s more sheltered southern coastline.
Porto and Braga, in the north, are noticeably cooler. Porto’s summer highs peak around 24°C (75°F), a full four degrees below Lisbon. Winter nights drop to about 6°C (43°F), and the persistent cloud cover can make it feel colder. Braga, slightly inland, swings a bit wider: warmer in summer at 26°C but colder in winter, with lows near 5.5°C.
The interior can go to extremes. Portugal’s all-time high temperature, 47.3°C (117°F), was recorded in Amareleja, a small town in the southeastern Alentejo, during the deadly 2003 European heatwave. The all-time low, minus 16°C (3°F), came from Penhas da Saúde in the Serra da Estrela mountains in 1954. These are outliers, but they show how much the interior diverges from the temperate coast.
Rainfall: The North-South Divide
The contrast in rainfall across Portugal is striking. The Braga region in the far northwest receives up to 1,934 mm of rain per year, roughly the same as famously wet cities like Bergen, Norway. The Algarve coast around Faro gets just 411 mm, putting it closer to semi-arid territory. Lisbon sits in between at roughly 700 mm.
Most of that rain falls between October and March. Summers across the entire country are reliably dry, especially from June through August when weeks can pass without a drop in Lisbon or the Algarve. Even Porto, which has a reputation for grey skies, sees very little summer rain. The wet season returns in autumn, often arriving suddenly with heavy downpours rather than steady drizzle.
Why Summers Are So Dry
A massive high-pressure system parked over the North Atlantic, known as the Azores High, is the engine behind Portugal’s weather. This persistent ridge of high pressure steers rain-bearing storms away from Portugal during summer, creating the long, cloudless stretches the country is known for. In winter, the Azores High contracts southward, allowing Atlantic storm systems to push through and deliver the bulk of the year’s rainfall.
The size and position of this high-pressure zone fluctuate year to year, which is why some winters are wetter than others. Its influence extends well beyond Portugal, shaping precipitation patterns across all of western Europe.
The Nortada: Portugal’s Summer Wind
If you visit the western coast in July or August, you’ll quickly notice a strong, steady wind blowing from the north. This is the Nortada, a seasonal wind driven by the pressure difference between the Azores High over the ocean and a low-pressure heat zone over central Spain.
The Nortada has a powerful cooling effect on the coast. It pushes surface water offshore, pulling cold, deep ocean water up to the surface in a process called upwelling. That cold water, in turn, sharpens the temperature difference between land and sea, which speeds up the wind even more. This is why beach towns on the western coast, like Ericeira or Peniche, can feel surprisingly chilly in midsummer even when Lisbon, just inland, is baking at 35°C. If you’re packing for a summer trip to the coast, bring a windbreaker regardless of the forecast temperature.
Madeira and the Azores
Portugal’s two Atlantic archipelagos have their own distinct climates, both milder and more stable than the mainland. The ocean acts as a thermal buffer, keeping temperatures moderate year-round and preventing the kind of extreme heat or cold the interior experiences.
The Azores, located about 1,500 km west of Lisbon, have a notably wet climate with rain spread more evenly across the year. Temperatures at low altitudes stay mild, rarely dropping below 10°C in winter or climbing above 26°C in summer. Madeira, farther south and closer to the African coast, is warmer and drier, particularly on its southern slopes. The island’s mountainous terrain creates sharp microclimates: the north side is lush and rainy while the south side stays sunny and sheltered.
The two island groups are also diverging over time. Climate projections suggest Madeira’s annual rainfall could decrease by up to 35% by the end of the century, making its already drier landscape even more arid. The Azores, by contrast, may see wetter winters. Both archipelagos are expected to warm less than the mainland, with projected increases of less than 2.3°C in the Azores and less than 3°C in Madeira, compared to larger rises forecast for interior Portugal.
Best and Worst Times to Visit
For warm, dry weather across the whole country, June through September is the safest bet. July and August are the hottest and driest months but also the most crowded, especially in the Algarve and Lisbon. The interior Alentejo region can become uncomfortably hot in this period, with temperatures regularly exceeding 40°C.
Spring (April and May) and early autumn (September and October) offer a sweet spot: warm temperatures, fewer tourists, and landscapes that are green rather than scorched. Rain is possible but usually comes in short bursts rather than all-day events. Winter travel works well in the Algarve and Madeira, where daytime temperatures stay above 15°C and sunshine is plentiful. Porto and the north, however, can be grey and soggy from November through February, with rainfall sometimes exceeding 200 mm in a single month.