The reason the northern European countries became far more successful in every way than their southern counterparts, and thereafter spread their cultures across the globe, lies with Martin Luther.
Luther wanted to reform the notoriously corrupt Roman Catholic Church. This sparked the protestant break-away, which fractured the formerly absolute power of the Church. As northern States began to see the advantages of being free from the many costs imposed by their subjugation to the Papacy, protestantism spread - and as it did so, it fragmented into numerous sects. Thus protestantism could not become a monolithic power like Catholicism, and therefore could not repress innovation in the same way.
Free from the dead hand of the Catholic Church, northern Europe exploded into life, both culturally and commercially. The Industrial Revolution followed, rendering the north supreme.
Today, so many years later, southern Europe is still socially and economically backward thanks to the lingering influence of Catholicism, while the north has spread its ethos around the globe.
So it's not anything to do with weather, but everything to do with a chance historical event.