When this is about the westernmost capital city in Europe, one can speak about the mainland or in general, this is about different cities.
Europe
What Is the Coldest Capital in Europe?
The term the coldest may imply the average temperature throughout the year or the lowest temperature in a particular winter month. In any case, the answer is below.
What Is the Warmest Capital in Europe?
If you are thinking of moving to the south and reducing your heating and living expenses, you will want to check this list of the warmest capitals in Europe.