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.