Lisbon Coast

The Lisbon coast is the Tagus mouth and the Atlantic shoreline either side of it — Cascais on one flank, Costa da Caparica across the bay. The tide here is one of the bigger ones on the Iberian Atlantic: mean range at the river mouth around 2.4 metres, with spring tides pushing close to 3.5 at the equinoxes. The pattern is cleanly semidiurnal, two highs and two lows about twelve and a half hours apart, and the river current adds noticeably to the ebb running past Algés and Belém. High water at Cais do Sodré in the city centre lags Cascais at the mouth by 30 to 60 minutes depending on Tagus discharge. Caparica's open beach narrows by 30 metres or more on the high and widens again on the low, so beach photographers and slow walkers head out at the bottom of the cycle. Open-Meteo Marine drives the gridded predictions on this site; Instituto Hidrográfico is the authoritative Portuguese tide source.