In the north and north-central regions, an umbrella is required
The sight of Porto in the early hours of the morning can sometimes be disconcerting. A thick fog envelops the city, even in summer, before dissolving as the day progresses. The Dom Luis Bridge seems to be thrown into the clouds. This fog is sometimes the cause of flight delays to and from Porto (quite frequent), as it disrupts air traffic. The north is Portugal's wettest region. Rainfall reaches up to 1,450 mm per year in Braga, 1,100 mm per year in Porto and 900 mm in Coimbra. It is very abundant between November and February, and rather scarce in summer. In winter, snow blankets Guarda, Bragança, Vila Real and Viseu. The sun shines for an average of 7 hours a day in the north, and up to 11 hours in summer. Temperatures can be chilly, so it's a good idea to carry a sweatshirt with you at all times. In Porto, temperatures range from 5°C in January to 25°C in July and August. On this side of the coast, the ocean is cold, with a maximum of 18°C in July. The wind is also a frequent visitor. In October 2018, Hurricane Leslie, Portugal's most powerful storm since 1842, ravaged the central and northern coastline. Gusts of 176 km/h were recorded in Figueira da Foz. Fortunately, residents were able to protect themselves as best they could, despite extensive material damage and a few injuries.
Inland to the north, east of Coimbra, between Viseu and Guarda, lies Portugal's largest nature park (101,000 hectares), Serra da Estrela and its highest peak, the Torre, which rises to 1,993 metres. The higher you climb, the wetter and colder it gets. It's the same as in the French mountains, winter and summer alike. Portugal's one and only ski slope can be found here.
The Douro Valley, protected from the influence of the ocean by its relief, enjoys a tropical microclimate. Summers are hot and dry, winters cooler and wetter. As you move upstream, rainfall becomes less frequent and temperatures rise. Thermometers average 15°C. It rains three times less than in Porto, but enough to produce good harvests. Leaving the city for the Douro Valley, fine weather is (almost) always guaranteed.
Bragança, which lies near Montesinh Park in the far north-east, experiences huge temperature variations, from -10°C in winter to 29°C in August, when there's no heatwave.
Lisbon to the rhythm of the Mediterranean climate, although on the Atlantic coast
In central and southern Portugal, winter is milder thanks to the Azores anticyclone which sometimes reaches the Portuguese coasts even in winter. Summer is warmer, with fewer oceanic disturbances and windy days. Although rainfall decreases as one moves southward, precipitation remains frequent in the Tagus Valley, near Lisbon (about 710 mm per year) following the rhythm of the Mediterranean climate: abundant in autumn and winter, moderate in spring and almost non-existent in summer. Winter, from December to February, is mild: the average temperature in January is 11.5°C. Daytime temperatures are generally pleasant, around 15/16 °C. The spring months from March to May can experience periods of bad weather that end in April. The difference in temperature between summer and winter is small. On average it is 23°C in Lisbon in July and August, with the Atlantic breezes tempering the heat. On the Lisbon coast, swimming without a wetsuit also requires courage. The temperature of the ocean is around 18°C all year round, with a peak of 20°C in August and September.
In the Vale do Guadiana Natural Park, in the Alentejo region of southeast Portugal, the average temperature is 18°C.
The South and the Algarve, between good and too much heat
Shorts, swimsuit, light T-shirt, flip-flops, sun cream - the Algarve best represents the postcard image of a warm, cloudless Portugal, inviting you to laze around. Along the south-facing Atlantic coast, in towns such as Lagos, Portimão, Albufeira, Faro and Tavira, summers are hot and dry, winters mild and very, very rarely rainy. Nevertheless, as soon as it rains, the annual dose recorded in the region (on average 500 mm per year) seems to pour down on the Algarve. The torrential rains of 2015 and 2017 come to mind. Flooding and mudslides caused extensive damage, particularly in the historic center of Albufeira. The ocean breeze eases the heat in coastal towns.
But in the central and southern interior, summer is very hot, especially during heat waves from Africa. In Beja, in the Alentejo region, temperatures between June and September can reach 40°C. In July 1995, 46.5°C was recorded in Amareleja, in the Beja district, in the central-east. Since the infamous scorching summer of 2003, temperature records have been broken again and again. From the arid centre-east to the centre-south, firefighters battle forest fires every summer.
For a trip to Portugal, it's a good idea to pack clothes suited to different weather conditions: in fine weather, shorts, Bermuda shorts and light pants, T-shirts and shirts for the day, swimsuits or even wetsuits for the more chilly, and a cardigan or sweater for cooler evenings; in mid-season and winter, warm, windproof and waterproof clothing.
