Sea level records on the Finnish coast

Sea level extremes measured in Finland, theoretical mean water as reference. Most of the sea water level observation stations, mareographs, have been measuring since the beginning of 1900's.

When referenced to the theoretical mean water (MW), the extremes mainly consist of variations caused by weather conditions. Ignoring small changes in weather conditions, such extremes roughly represent the expected sea level variability of the present day too.

Station Maximum (date) Minimum (date) Since
Kemi +201 cm (22.9.1982) -128 cm (14.1.2016) 1922
Oulu +183 cm (14.1.1984) -131 cm (14.1.1929) 1922
Raahe +162 cm (14.1.1984) -129 cm (4.10.1936) 1922
Pietarsaari +139 cm (14.1.1984) -113 cm (4.10.1936) 1922
Vaasa +144 cm (14.1.1984) -103 cm (2.1.2019) 1922
Kaskinen +148 cm (14.1.1984) -92 cm (2.1.2019) 1926
Pori +132 cm (14.1.1984) -86 cm (2.1.2019) 1925
Rauma +135 cm (22.2.2020) -80 cm (2.1.2019) 1933
Turku +130 cm (9.1.2005) -74 cm (10.4.1934) 1922
Föglö +102 cm (14.1.2007) -71 cm (10.4.1934) 1923
Hanko +133 cm (9.1.2005) -79 cm (28.1.2010) 1887
Helsinki +151 cm (9.1.2005) -93 cm (28.1.2010) 1904
Porvoo +123 cm (6.12.2015) -69 cm (7.3.2017) 2014
Hamina +197 cm (9.1.2005) -116 cm (20.3.2013) 1928

Referenced to the theoretical mean water

If referenced to other height systems like N2000 (= BSCD2000), for example, the record would tell how high or low the water would have been related to the ground. As the average sea level slowly changes in relation to the ground, such extremes are more time-dependent than those given in relation to the theoretical mean water (MW). That´s why the extremes that have occurred in the past decades might not represent the expected sea level variability of the present day and are not presented here.

20.9.2021