Wind influences the speed that a fire will spread, the direction in which it travels and the size of the fire front, its intensity and the likelihood of ‘spot fires’ from embers ahead of the main fire.

Wind direction can determine how a bushfire may ‘run’ (move) through the landscape.

Wind can travel in all directions, but there are typical weather patterns that are likely to influence bushfire behaviour, particularly on days where a bushfire is more likely. A change in wind direction is one of the most dangerous influences on fire behaviour.

In Victoria, the most dominant winds typically come from the north and north-west. They are often followed by a south-west wind change. A wind change like this can cause a shift in the direction of the fire. This means what was a slower burning ‘flank’ (side section) of a fire becomes the head (front) where more intense fire behaviour occurs.

During Black Saturday, a south-westerly wind change at the head of the fire impacted access routes. People’s ability to leave was changed.  New fire fronts were created putting more areas at risk.

Afternoon sea breezes often affect coastal areas. They are caused by the difference between temperature on the land and the sea, with the movement of warmer air towards land.

Key consideration for planning decision making:

Wind direction is a key consideration as part of the bushfire hazard landscape assessment and requires a wind direction diagram.

This provides a visual of the dominant winds to be expected across Victoria. In areas affected by coastal winds add a second wind direction diagram.

Fire spread and wind change in a bushfire diagram - two images one of wind blowing from the north onto the narrow side of the fire; and the second showing a wind change to blowing from the south west and the longer eastern flank of the fire becomes a much larger fire front.

Page last updated: 25/01/22