The BBC confirmed that the Twitter account was one of its own and had been hacked. No further details were immediately available.
The hackers identified themselves as members of the Syrian Electronic Army, a group that has carried out a string of web attacks against targets such as Al-Jazeera, which it sees as sympathetic to Syria's rebels.
Among the messages posted by the BBC Weather Twitter account on Thursday were "Long Live Syria Al-Assad"and "Saudi weather station down due to head-on collision with camel."
A further message claimed Turkish leader Recep Tayyip Erdogan ordered terrorists to launch chemical weapons at civilian areas in North Syria.
The hackers posted about 10 messages before signing off. All of the tweets were later deleted.