Right now the warmest water is in Funchal at 24.8 °C, and the coolest in Lagos at 17.7 °C.
The sea around Portugal varies far more than the air. In summer the Atlantic along the west coast rarely climbs past 18 °C, while the Algarve reaches 19 to 21 °C and Madeira stays mild almost all year round. This page shows today's water temperature and wave height for the main cities and beaches along the coast.
Tap any city to open its full page, with an hour-by-hour weather forecast, the water trend for the coming days and the typical climate for each month.
Between August and October. The ocean warms slowly and peaks in late summer, well after the hottest air of the year. In the Algarve, September often has warmer water than June.
Why is the water so cold on the west coast?
Because of coastal upwelling. The summer northerly wind pushes surface water offshore and pulls cold deep water up in its place, so the west coast can turn several degrees colder from one day to the next.
Where is the water warmest: the Algarve, Madeira or the Azores?
Madeira and the Azores, at around 24 °C in late summer. On the mainland the eastern Algarve leads, near 21 °C around Tavira, while the rest of the Algarve sits at 18 to 19 °C and the west coast stays closer to 17 to 18 °C. In winter Madeira is the mildest by far and rarely drops below 19 °C.