Authorities have been evacuating people from areas in central and western Victoria as dangerous fire conditions grip several states across the south-east.

Damaging winds were due to fan extreme fire danger on Thursday as hot and dry weather envelops large parts of Victoria, south-west New South Wales and much of eastern South Australia.

Early on Thursday afternoon, Victoria state control centre spokesperson Luke Hegarty said the extreme fire conditions forecast were already starting to develop, with the potential for strong, gusty winds to start new fires, and spread existing ones towards communities not currently subject to warnings.

“This is a critical part of the day. If you don’t need to travel, please postpone your plans,” he said.

“Over the next few hours, we expect the northerly winds to continue to strengthen, which will mean that any fire that is burning will spread, and then we have the real risk later in the day, in the early evening through to night time when the southerly wind change will hit the state.”