The declaration, which gives the state and emergency services additional powers, was put into place last Thursday.
Mr Andrews said the extension was needed to manage what was likely to be a significant increase in bushfire activity over the next 48 hours.
The state of disaster covers East Gippsland, the Alpine region and the state's north-east.
Authorities are urging people to leave the Alpine region and all areas east of Bairnsdale, in East Gippsland, as the fire danger once again ramps up.
