"Roedd hi'n wyntog ddoe."
Translation:It was windy yesterday.
February 22, 2016
No, that phrasing doesn't really make any sense. If you add a bod yn and take away ddoe it makes sense but doesn't mean the same thing as the sentence given:
- Mae hi wedi bod yn wyntog - It has been windy
We use roedd for describing the general weather which continued for a while in the past:
- Roedd hi'n oer/dwym/wyntog/bwrw glaw - It was cold/warm/windy/raining