Hanko tide times

Hanko (Swedish: Hangö) is the southernmost town in Finland, at the tip of a narrow granite peninsula extending south into the Baltic. The geography is emphatic: the peninsula runs roughly 30 kilometres south-southeast from the mainland, narrowing as it goes, and Hanko sits near the southern end. It is the closest point of Finnish territory to the shipping lanes of the central Baltic and the entrance to the Gulf of Finland.

The town also records the highest annual sunshine hours in Finland, a function of the open exposure and the tendency for cloud to clear over the sea. Sandy beaches face the open Baltic on the south and southwest shores of the peninsula; the longest is Itäinen Pitkäniemi (Eastern Long Point Beach), a several-kilometre stretch of Baltic sand backed by pine forest. The beach faces south-southeast; it catches the afternoon sun through to evening in summer.

The water here is the southern Baltic — less saline than the North Sea, clearer than the inner Gulf of Finland, warm in July and August (19 to 22°C in a typical summer, occasionally 24°C in extended heat). The astronomical tide at Hanko is essentially zero. The Baltic Sea is an enclosed basin and the tidal range here is 2 to 5 centimetres — below the threshold of any practical relevance for beach use, swimming, sailing, or angling.

The water level on any given day at Hanko is determined by weather: wind direction and strength, atmospheric pressure, and the seiche oscillation of the Baltic basin (a standing wave with a natural period of roughly 27 hours that adds or subtracts tens of centimetres at any coastal point). A sustained westerly pushes water into the Gulf of Finland and raises levels at Hanko and along the Finnish coast generally; an easterly draws it back. The FMI (Finnish Meteorological Institute) Hanko tide gauge is a long-term reference station in the Finnish sea-level monitoring network; the gauge record is one of the longer continuous records on the Gulf of Finland and contributes to Baltic sea-level rise assessments.

FMI publishes real-time sea-level observations and short-range water-level forecasts through its open-data service. Hanko has a well-documented WWII history. The Moscow Peace Treaty of March 1940 that ended the Winter War required Finland to lease the Hanko peninsula to the Soviet Union for 30 years as a naval base; Soviet forces occupied Hanko from March 1940 to December 1941.

Finnish and Soviet fighting for the peninsula in the Continuation War (June 1941 onwards) left fortifications, gun emplacements, and memorial sites across the peninsula that are accessible to walkers. The Soviet evacuation of Hanko in December 1941 under Finnish and German naval pressure is commemorated at the Hangon Linnoitusmuseo (Hanko Fortification Museum). Sailing is central to summer Hanko: the Hanko Regatta (Hangö Regattan) is the largest sailboat race in Finland, drawing hundreds of boats annually over a course in the outer archipelago.

The absence of tide is characteristic: the sailing calendar is built around wind and weather, not tidal windows. Fishing from the peninsula rocks and from small boats targets perch, pike-perch, and Baltic herring; the solunar tradition has followers here as it does in other Finnish coastal fishing communities, though the angler tradition's predictions are no more or less reliable than elsewhere. Predictions on this page come from Open-Meteo Marine, a gridded global ocean model.

3 metres on height — substantially exceeds the actual tidal signal. The values shown represent weather-driven and seiche water-level variation.