Can't get much colder or wintery than Finland, Denmark, and Norway, but
> For the second year in a row, the world's happiest country is... Finland!
> Finland topped the list of 156 countries, which were ranked in the United Nations Sustainable Development Solutions Network's 2019 World Happiness Report. The report ranks countries on several well-being variables including income, freedom, trust, healthy life expectancy and more.
> Two other Nordic countries came in second and third place, Denmark and Norway, respectively.
From https://www.usatoday.com/story/travel/news/2019/03/20/finlan...
Meanwhile, in the tropics:
> On the other hand, South Sudan ranked the least happy on the list.