No we have the Atlantic warm streams from the canal between GB (UK) and France and the influence of the Atlantic Water coming from the North-West of Scotland and England with it's warm streams. They say that the UK and the Netherlands receive the weather of the Azores. It chills a bit during the journey, but it doesn't get that cold. But occasionally we get very tough winters with influences from the East (Germany/Poland), the South (Belgium and France) or the North (Scandinavia).
The average temperature on the North sea in the summer is 17 °C (63 °F) and 6 °C (43 °F) in the winter. The average temperatures have been trending higher since 1988, which has been attributed to climate change. Air temperatures in January range on average between 0 to 4 °C (32 to 39 °F) and in July between 13 to 18 °C (55 to 64 °F). The winter months see frequent gales and storms.
The salinity averages between 34 to 35 grams of salt per litre of water. The salinity has the highest variability where there is fresh water inflow, such as at the Rhine and Elbe estuaries, the Baltic Sea exit and along the coast of Norway.
I believe the Baltic sea is a bit colder than the North sea. There will be influence of Artic ice in the Nordic part of the Baltic sea coming from the Gulf of Bothnia.