Europe also spans some extreme weather, from the frozen North to the scorching hot Meditarranean.
I am from Spain, where 40ºC in summer is normal but winters are mild. I have friends and colleagues from Finland and Latvia, which are pretty much the opposite. And yet all our countries are walkable.
And like in the US, population is mostly concentrated in the spots where it's not that extreme, so that's where most people are/would be able to benefit from human-centred urban design.