About the charts

The ice chart of the whole Baltic Sea (pdf) is published in the autumn twice a week (Monday and Thursday) and daily when the amount of ice increases until until ice break-up in spring. It represents current ice situation, ice breaker positions and traffic restrictions in the Baltic Sea.

The simplified charts are updated once a week at the latest on Tuesday morning. The first one represents measured level ice thicknesses, ice coverage and sea surface temperature. The reference charts represent average, 1965 – 1986, ice situation on that day (= normaali), last week´s situation, last year´s situation and the positions of the ice breakers.

Explanation of chart's finnish words

• jäätä: ice
• vettä: water
• haurasta: rotten ice

More Information

• Scientific themes - Sea ice
• Finnish Environment Institute: Lake ice conditions
• Baltic icebreaker management
• CMEMS: Ice chart data in netcdf format
• Marine weather: Sea water temperature