In addition to the Gulf Stream, other factors that contribute to the warmer climate in Northwestern Europe include the prevailing wind patterns and the location of the land masses. The prevailing winds in Northwestern Europe are from the west and southwest, which means that they come from the warm waters of the Atlantic Ocean. This helps to keep temperatures in Northwestern Europe mild. In contrast, the prevailing winds in Eastern North America are from the northwest, which means that they come from the cold waters of the Arctic Ocean. This helps to keep temperatures in Eastern North America cold.
Finally, the location of the land masses also plays a role in the different climate between Northwestern Europe and Eastern North America. Europe is located closer to the equator than North America, which means that it receives more direct sunlight. This helps to keep temperatures in Northwestern Europe warmer.