Ice conditions

Normal situation Previous ice map Ice map of the previous year Icebreakers

Normal situation


The ice drifts north.

In the northern Bay of Bothnia 30-55 cm thick fast ice in the archipelago. Off the fast ice there is ridged, 20-45 cm thick compact drift ice to approximately 2 nautical miles southwest of Bothnia buoy and to Nahkiainen. At the edge of the ice field there is a brash ice barrier, difficult to force. Farther out new ice.

In the southern Bay of Bothnia in the archipelago 25-45 cm thick fast ice. Off the fast ice there is first 2-10 nautical miles wide lead with very open ice. Farther out 10-25 cm thick ice with varying concentration, thin level ice and new ice to the Quark.

In the Quark 15-40 cm thick fast ice in the archipelago. Farther out in places 5-30 cm thick drift ice approximately to Norrskär.

In the Sea of Bothnia 10-35 cm thick fast ice in the archipelago. At the fast ice edge there is in places thin very close ice, new ice and shuga.

In the Archipelago Sea thin ice in the inner archipelago. In the fairways mostly open water or very open ice.

In the western Gulf of Finland thin fast ice in the inner archipelago. Further out there is thin very open ice.

In the eastern Gulf of Finland 15-40 cm thick fast ice in the inner archipelago. In the outer archipelago mostly 5-25 cm thick very open ice. In the Gulf of St. Petersburg and the Gulf of Vyborg, 20-35 cm thick ice, farther out 5-20 cm thick ridged consolidated ice.

Icebreakers: Kontio, Otso, Sisu and Frej assist in the Bay of Bothnia. Zeus assists in the Bay of Bothnia as well as in the northern Sea of Bothnia. Voima assists in the Gulf of Finland.

Restrictions to navigation: Minimum ice class and deadweight required of assisted vessels:
Tornio, Kemi, Oulu and Raahe, IA of more than 4000 tons.
Kalajoki, Kokkola, Pietarsaari and Vaasa, IA and IB of more than 2000 tons.
Kaskinen, Loviisa, Kotka and Hamina, IA and IB of more than 2000 tons and IC and II of more than 3000 tons.
Kristiinankaupunki, Pori, Rauma, Uusikaupunki, Naantali, Turku, Taalintehdas, Förby, Hanko, Koverhar, Inkoo, Kantvik, Helsinki and Sköldvik, I and II of more than 2000 tons.

Vessels bound for Gulf of Bothnia ports in which traffic restrictions apply shall, when passing Svenska Björn, report their nationality, name, port of destination, ETA and speed to ICE INFO on VHF channel 84. This report can also be given directly by phone +46 31 699 100.

Finnish transport agency makes a decision regarding vessel traffic operation in the Gulf of Finland 9 meters archipelago fairway. North of island Bodö between Lästholm - Långholmen meeting and overtaking by any vessels is prohibited due to an ice-road and/or ice-bridge. The speed limit is set to 9 kilometres per hour (5 knots).
This decision concerns all vessel traffic.

The reference map can be changed by clicking on the links above the images. The different maps show the average (= normal) ice conditions (1965-1986) for the period in question, the ice chart of the preceeding week, the corresponding ice chart for the previous year, and the current location of Finnish icebreakers.

The Baltic Sea Now pages display a simplified map of the sea areas by Finland. This map is updated weekly, by Tuesday morning at the latest. The map shows the areas covered by ice and the thickness of smooth ice in these areas. In addition, the map includes isometric displays of temperature gradients by area.

When the Baltic is not covered by ice, the maps show the surface water temperatures in the sea areas and the corresponding temperatures from the previous year. During ice-free periods, the maps are updated irregularly.

More information

Explanation of map's finnish words

  • jäätä: ice
  • vettä: water
  • normaalitilanne: normal situation
  • ahtauma: ice ridge
  • haurasta: rotten ice