It think that it was a lot earlier than that - there's a great deal to suggest that Irish and British sailors got there well before, and there was (I reckon) regular fishing off Newfoundland well before Spanish settlement,organised by such people as the Bristol businessman Ap Meurig, whom the Bristolians called Amerig. Perhaps the real contact was limited, though we were always told that Prince Madoc founded a whole tribe over there. Who can tell!Yes, diseases were exchanged between both cultures.
but the colonization did not begin until the 1500s. 200 years after the beginnings of the little ice age.
There is evidence that the Vikings discovered the Americas few 100 years before Columbus.
The Vikings could not colonize the Americas because the fall of the Nordic sea power ended with the Little Ice age..