Native to BlackBerry 10 we have a vast selection of weather applications and in fact all new devices come pre-loaded with BlackBerry Weather that is powered by AccuWeather. But if you fancy a change and you're in the UK you may want to hit up the Met Office app. You won't find it in BlackBerry World though as it's an Android app, but if you're running BlackBerry OS 10.2.1 you can just install the APK from the likes of Snap.*
Except of course it is full of adverts and is incredibly slow to load weather information.
It's not quite as bad as the BBC weather app which thankfully has no adverts but difficulty displaying information a lot of the time (i.e. Switching between days keeps the same forecast).
I can't find a decent weather app for the UK at all for my Q10, hence why I have found this unhelpful post promoting such a terrible app.
Sorry to be so negative but I felt it needed corrected!