Sea Level Statistics
Sea water level is measured at mareographs (tide gauges) along the Finnish coast. In Finland, the most important factor affecting sea level variations is wind, and extreme sea levels are thus measured during stormy weather. The variations also depend on location. Largest sea level variations occur in the ends of the bays; on the Finnish coast in the Bay of Bothnia and eastern Gulf of Finland. The variations are smallest in the central Baltic Sea, which means in Finland the Sea of Åland and the Archipelago Sea.
30-year Statistics
The graphs below present statistics calculated from the sea level observations 1991–2020. The highest and lowest sea water levels from every station and the 30-year averages are presented as solid lines. The averages of the annual maxima and minima 1991-2020 are presented as dashed lines. The highest and lowest annual averages are presented as dotted lines. The values are calculated in two height systems. On the first graph the values are referenced to the theoretical mean water (MW) and on the second to the N2000-system. The N2000 system is based on precision levellings and fixed to land. On the other hand, the height system MW approximately follows the average sea level. The height systems differ from one another as the average sea level changes in relation to fixed land due to e.g. land uplift and global sea level rise.
28.2.2025