Sea observations

SMHI carries out real-time observations of oceanographic parameters with tide gauges, buoys and vessels. Data are collected every hour and presented within 30 minutes. Measurement are also conducted with vessels where sevral biogeochemical parameters are acquired.

Sea level

SMHI presents sea level measurements from 24 tide gauges (sea level stations). The sea level is measured in a local height system and values are presented relative the theoretical mean sealevel, a level calculated from many years of annual means, which takes into account the effect of land uplift and sea level rise. The values are averaged over 10 minute periods.

Sea level

Sea surface temperature

SMHI presents the temperature near the surface from four sea buoys and a five tide gauges. The values are averaged over 10 minute periods.


The wave height is given as the distance in metres between the wave trough and the wave peak. Four buoys measure waves. A wave sensor is mounted inside the buoy which measures the wave height, direction (the angle from which the waves come) and wave period (seconds). The values are based on observations over a 30 minute period.


Currents are measured and reported from two stations, one in the Baltic Sea and one off the west coast.