Cascais-Portugal.com
The best independent guide to Cascais
Cascais-Portugal.com
The best independent guide to Cascais
Cascais weather and when to visit
Cascais is a wonderful holiday destination that offers stunning beaches, varied sights and many excellent restaurants, bars and cafés. I would be so bold as to say it is possibly the best beach destination in Portugal, and I have recommended it to friends and family for years.
The Lisbon coastline enjoys a classic Mediterranean climate, featuring hot, dry summers and mild winters. The weather is reliably fine for spending time on the beach from mid-May until the end of September. The tourism season broadly begins around Easter, though April can be notoriously wet.
The peak months are July and August. July is busy as it marks the start of the surprisingly long Portuguese school summer holidays, while August brings the additional wave of foreign tourists.
I love Lisbon, and by extension Cascais, in June. The weather is pleasantly hot, the summer crowds have not yet arrived, and across Lisbon the Festas de Santo António are in full swing. They are easy to reach from Cascais on the regular train to Cais do Sodré, making a night out in Lisbon a simple and memorable addition to a Cascais holiday. September shares that same glorious weather but tends to be a touch busier, as visitors book late summer getaways once the school holidays have ended.
At the other end of the year, winter can be very wet in Cascais, with days of solid rain and grey skies. That said, there are bargains to be found, and with some flexibility an enjoyable holiday can still be had. Cascais has a large permanent population so all restaurants, bars and shops stay open year-round.
I have been visiting Cascais since 2001 and have lived in nearby Lisbon with my Portuguese wife since 2020. This guide will detail the weather of Cascais month by month, when to visit and what to expect from each season.
Cascais weather
Cascais enjoys a Mediterranean climate heavily influenced by its position on the Atlantic Ocean. This means the town is spared the blistering heat found in the interior of Portugal but it also experiences strong winds at exposed locations such as Guincho beach, and year-round chilly sea temperatures.
Temperature
Official statistics have daytime temperatures reaching a maximum of 27°C in August, but these values never really tell the true story of what it feels like, as they measure air temperature in the shade. Lying out in the midday August sun, it will feel significantly hotter than 27°C.
During summer evenings there is often a refreshing breeze, but once night sets in and the wind drops, the humidity makes it feel like the temperature has risen. In the summer you will want air conditioning, though I do not have this in my flat in Lisbon and it is manageable.
While researching this guide I kept stumbling upon the statement that Cascais remains pleasantly warm due to the "Nortada", a cooling north-westerly wind that acts as nature's air conditioning. Yes, there is the north wind, but it will still be very hot in Cascais, and the town's sheltered position means you barely feel it. Simply put, Cascais will be very hot from mid-June to the end of August.
One thing that catches out many visitors in winter is the humidity. A forecast of 15°C may sound pleasant, but the damp sea air always makes it feel cooler, especially if a breeze is blowing.
Rainfall in Cascais
Rain in Cascais is highly seasonal and can be summed up as all or nothing. From June through August, rainfall is almost non-existent, often recording less than 5mm per month.
The wet season begins in late October and peaks in November and December, though in recent years it has dragged on into February. The wet weather is best described as unpredictable: there could be a spell of clear, fine weather for five days, or equally a stretch of solid rain. During these months, Cascais receives the bulk of its annual rainfall, often in the form of heavy Atlantic fronts.
The one month to be aware of is April, due to the brief but intense downpours. My wife, like most Portuguese, will mutter with disgust when caught in an April shower: 'Em Abril, águas mil' (in April, a thousand waters). April is surprisingly wet as the high-pressure system called the Azores High has not yet formed, and the warming land draws moisture-laden clouds in from the Atlantic. By mid-May the Azores High has established itself and the wet weather is pushed northwards.
Insight: I feel official statistics for "days with rain" can be very misleading, as a day is counted if there is even the lightest amount of rainfall. In practice, there is no real rain from May to September.
Sunshine
Cascais does have a lot of sun in the summer with the region boasting over 2,500 hours of sunshine per year. Again, this is the mix between the hot dry summer when there can easily be 12 hours of sunshine, versus the winter which may not see it for days.
Have you booked your hotel?
Cascais is one of the most popular holiday destinations in Portugal, and good accommodation books up quickly, particularly for June to September. I would always recommend booking as early as possible to get the best choice and prices.
The map below displays hotels and accommodation in Cascais. Adjust the dates to your holiday to see current prices and availability.
Beach days
I consider a day suitable for the beach or lounging by the pool when there is full sun and the temperature is above 21°C. This weather is reliably consistent from May until the end of September.
Winter weather (December to February) rarely produces days that I would count as suitable for the beach. Any bright, sunny days during this period are better suited to activities or sightseeing.
Cascais Sea Temperatures
The sea at Cascais is chilly almost year-round, as it is fed by the Atlantic Ocean. The influence of the ocean means temperatures remain remarkably consistent, fluctuating by only around 5°C to 6°C throughout the entire year and reaching just 21°C at the peak of summer. On a scorching summer's day this cold water provides incredible relief, but most casual swimmers find it a bit bracing at first touch.
Even when I go surfing at the Costa da Caparica during the summer months, I wear a full body wetsuit, as spending extended time in the water will chill you.
The winds of the Serra da Sintra
If you take any trips along the Serra de Sintra, such as to the Cabo da Roca headland, Guincho Beach, or the pretty villages of Azenhas do Mar and Praia das Maçãs, be prepared for it to be chillier than in Cascais.
Cascais is sheltered from the strong Atlantic winds; however, places like Cabo da Roca are exposed to them and will feel unexpectedly cool. In the summer, you will want an extra layer for Cabo da Roca, but in the shoulder seasons (spring and autumn), be prepared for it to feel significantly cooler due to the high moisture in the air and strong winds.
While at Cabo da Roca, I frequently hear tourists complaining, "It's so chilly!", while dressed in only light summer clothes.
Our most popular guide for Cascais and Lisbon
Expert Insight: These guides are curated by Philip Giddings, a travel writer with over 25 years of local experience in Portugal. Since 2008, Phil has focused on providing verified, on-the-ground advice for the Cascais region, supported by deep cultural ties through his Portuguese family. Read the full story here.
Cascais-Portugal.com, Sintra-Portugal.com and Lisbon-Portugal-Guide.com with over 800 pages,
if its not here its probably not in Cascais, Estoril or the Lisbon coastline!
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