It's not so harsh in Norwegian West, East and South as to be remarkable in any respect. Poland has rougher climate. Northern parts and central-inland in the peninsula are cold, but relatively sparsely populated.
Norway has its natural limitations though which made for a tougher life. Like insufficient options for agriculture, one thing that made feudal system here impossible and diets fairly lean.
Norwegian climate is not so harsh that it makes life an perpetual fight for survival. But it's nasty enough to slap one's lazy nose every once in a while.