Because aircraft must take off and land into the wind for safety reasons, the runway selected for use will be the one that allows “into-wind” operations. 

Wind patterns tend to be seasonal.  This means that at some times of the year a runway and its associated flight paths may receive more use than at other times of the year.

The following image outlines the seasonal wind patterns and how they vary around Australia.

Our fact sheet on Seasonal weather patterns explains this in more detail.