The height of a wave is the difference between its trough and its peak. During the ice-free season, wave height is measured in real-time using wave buoys. The significant wave height, which corresponds to the visually observable wave height, can be calculated from the wave height measurement results. The highest individual waves are almost double the significant wave height. These buoys are brought back to land each year before the sea freezes. The size and shape of the Baltic Sea affect what kind of waves can grow there.

How to use the graphs

By clicking the station on the map, list or diagram, the last 2 weeks observations about significant wave height can be seen as well as the latest wave direction.
On the diagram, setting the mouse on a station shows the latest significant wave height measured and behind it with a grey column the highest significant wave height ever measured on that station.