Question

why north europe is warmer than north-easter america

Answer 1

It was thought that Western Europe is kept warmer than it's latitude would suggest because of the Gulf Stream, which shoots warm equatorial waters up along the eastern coast of North America and across the North Atlantic to Europe.

Answer 2

The gulf stream is one of the reason,
The Gulf stream runs south from the gulf of mexico to Europe, carrying the warmth. That's why this region is warmer.