I realy love the norwegian weather service, yr.no (Has english language selection on top). It works worldwide and has an open API [1]. Not sure where they get the data though but short term it's very good here in Sweden. Long term tends to be a bit exagerated though but improves the closer it gets.

[1] https://hjelp.yr.no/hc/en-us/categories/200450271-About-Yr-t...