Sea Records

Wave Records

The highest significant wave height measured with wave buoys in Finnish sea areas.

The wave observation network is quite sparse. Wave height is measured with wave buoys, which are very challenging to install and maintain in the middle of the sea in comparison to onshore weather stations. The ice makes it even more difficult in the Baltic Sea. The buoys don´t stand the ice, so they must be taken off in the wintertime. Therefore, there is not as long timeseries of the waves as of many other observations. The records are of the significant wave height, which present the height of all waves better than the single highest wave.

Wind Records

Average wind speed at sea: 33.5 m/s

The maximum 10-minute mean wind speed measured in Finland at sea is 33.5 m/s. It was measured at the Kylmäpihlaja observation station in Rauma on 1st November.2024. This is the first time that a 10-minute mean wind has been measured to be the speed of a hurricane (at least 33.0 m/s). The previous record of 32.5 m/s was recorded at the Bogskär observation station in Kökar on 2nd January 2019.

Gust record 41.6 m/s

In the era of automatic observations, the strongest gust in Finnish sea areas was in the storm named Aapeli on 2nd January 2019, when the Bogskär station in Kökar measured 41.6 m/s.

Water Level Records

The highest and lowest seawater levels measured in Finland. In the last column is the year from which there are observations from the station.

Water levels are referenced to the theoretical mean water. That´s how they describe how high or low the water has been in the harshest weather conditions. In height systems other than theoretical mean water, the interpretation of record readings differ. For example, the highest and lowest seawater levels measured in the N2000 height system would indicate how high the water has been relative to the ground. Because of the land uplift and the global sea level rise, these water levels are very time-dependent, and record-numbers are not as meaningful for them.

Ice Records

Thickest fast ice measured: 122 cm in Röyttä on 21st April 1985.

Seasons largest ice situation in the Baltic Sea: Largest: 422,000 km² Smallest: 37,000 km²

The severity of an ice season is usually described according to the largest ice situation of the winter. In mild ice seasons, even the largest extent is less than 115,000 km² .

As largest, the ice has covered the entire Baltic Sea, covering an area of 422,000 km². The minimum ice situation has been 37,000 km² in the winter of 2020.