Portugal Temperature Map

Carcavelos sea water temperature

Sea water: 20.1°C, cooling slightly to around 19°C over the coming days

Waves: 2.2m

At 20.1 °C the water in Carcavelos is pleasant for swimming by Atlantic standards.

Sunrise: 07:03 · Sunset: 20:14 · Day length: 13h 11m

Sea temperature in Carcavelos for the next 7 days

Day Sea water Waves
Friday 28/08 20.1 °C 2.2 m
Saturday 29/08 20.0 °C 1.8 m
Sunday 30/08 20.4 °C 1.2 m
Monday 31/08 20.1 °C 1.3 m
Tuesday 01/09 19.3 °C 1.3 m
Wednesday 02/09 18.8 °C 1.0 m
Thursday 03/09 19.2 °C 0.9 m

Average sea temperature in Carcavelos, month by month

Month Average water
January 15.4 °C
February 14.9 °C
March 14.9 °C
April 16.1 °C
May 16.4 °C
June 17.9 °C
July 17.7 °C
August 17.4 °C
September 17.0 °C
October 18.2 °C
November 17.7 °C
December 16.0 °C

Monthly averages for 2022–2025.

This page shows the water temperature at Carcavelos today and over the next seven days, so you can pick the best beach day before you go.

Sea temperature moves much more slowly than air temperature. A hot afternoon does not warm the ocean, and a windy day can cool it fast. Checking the water itself is the only reliable way to know what to expect.

Carcavelos is the largest beach on the Estoril coast, about twenty minutes by train from Lisbon, with the São Julião da Barra fort anchoring its western end. It sits just outside the mouth of the Tagus and faces southwest, so it gets a little shelter from the worst of the swell but none from the upwelling. The water holds around 17 °C in August and can fall a couple of degrees within days when the northerly wind sets in, then peaks in September and October.

Frequently asked questions

When is the sea warmest in Carcavelos?

The water is warmest in October, averaging 18.2 °C, and coldest in February at 14.9 °C. On the west coast the peak arrives late, in early autumn, because summer upwelling keeps pulling cold deep water to the surface.

Why is the water colder than the air in Carcavelos?

The ocean gains and loses heat far more slowly than land, so it runs months behind the seasons. On top of that, the summer northerly wind pushes surface water offshore and draws cold deep water up in its place, which is why a heatwave on land so often coincides with a colder sea.

What can you do in the sea in Carcavelos?

Learning to surf is the main event, with schools lined up along the sand and manageable waves most days of the year. Beyond that there is bodyboarding, beach volleyball on the permanent courts and plenty of room for a long swim when the sea flattens off. Weekday mornings are far more pleasant than summer weekends, when half of Lisbon arrives on the train.

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