This report is an attempt to describe natural temperature variations around the Swedish coast. The data are collected partly from Swedish and Danish lightship observations, partly from measurements made by SMHI observers and recording instruments. The observational stations are concentrated around the southern coast of Sweden, which leaves the Gulf of Bothnia somewhat under-represented,

For comparison of large scale temperature variations in the different areas during different years, monthly mean temperature values during the years 1924-39 from several lightships around Sweden have been calculated. A geographical distribution has been made from the yearly cycle and certain features in the different areas have been established. Furthermore an attempt has been made to characterize the years during the period 1923-70 as warm or cold in an oceanographic sense and briefly evaluate the causal relations.

In order ta campare the "temperature shocks" caused by cooling water discharges with natural temperature variations, the maximum temperature variations during 1, 6 and 24 hours at different depths have been calculated. Temperature conditions along the Swedish coast have been studied by producing statistics of the thermocline´s strength and depth during different months and for different places.