
Portugal Sea Temperature in May
Historical 30-year sea surface temperatures across 44 coastlines in Portugal for May. Derived from NOAA 0.25° blended satellite and in-situ marine observations.
- Ranges 15.5°C at Praia de Miramar to 19.8°C at Porto Santo Beach.
- None of Portugal’s 44 surveyed coastlines reach the 21°C swim threshold in May.
- No month averages 21°C across Portugal as a whole, though 16 of 44 coastlines clear it in July.
- 3.5°C cooler than Portugal’s August peak of 20.7°C (see August).
Select Month
View 12-Month Annual Overview →Canary Current, Coastal Upwelling & The Nazaré Canyon
Despite sitting at Mediterranean latitudes, Portugal’s Atlantic coast and Algarve exhibit cool sea surface temperatures (averaging 18.5–20.3°C in August). Persistent northerly summer winds (the Nortada) push surface waters offshore, driving active coastal upwelling that draws deep, nutrient-rich ocean layers (14–16°C) to the shoreline. Off central Portugal at Nazaré, the continental shelf is bisected by the Nazaré Submarine Canyon (Canhão da Nazaré), a 230km long, 5,000m deep underwater chasm terminating just 1km offshore. In winter, this bathymetric trench acts as a hydraulic funnel, refracting and focusing North Atlantic storm swells into world-record 20–30m breaking waves at Praia do Norte.
Portugal Beaches in May
Individual coordinate lookups from NOAA 0.25° marine grid.










































