Veneto

The Veneto coast runs across the head of the Adriatic from the Po delta at the southern edge to the Tagliamento mouth in the north, with the lagoon city of Venice and its barrier-island system at the centre. The tide here is the largest in the Mediterranean by some distance — mean range at Punta della Salute in central Venice is about 0.6 metres, climbing close to 0.9 metres on the largest spring tides and the high-water peaks during sirocco events. The pattern is semidiurnal across the lagoon, two highs and two lows about twelve and a half hours apart. The lagoon connects to the open Adriatic through three inlets — the Lido, Malamocco, and Chioggia bocche — and the MOSE flood barriers across each can be raised when surge events threaten central Venice. The phenomenon of acqua alta — exceptional high water from the combination of spring tide, low atmospheric pressure, and sustained sirocco wind — is the defining tidal event of the city: the November 2019 peak ran about 187 cm above the local datum, the second-highest on record after the 194 cm event of November 1966. Walkways flood, raised passerelle go up, and parts of San Marco become tide pool. ISPRA's Centro Maree publishes the authoritative real-time forecast and historical record.