The first vineyards in Margaret River were planted in the undulating landscape created by the water courses of the ridge that connects Cape Leeuwin in the south and Cape Naturaliste in the north.
The streams of the ridge flow to the west, hence a significant influence on these vineyards is the late morning thermal winds in summer that drift on-shore from the Indian Ocean.
This breeze funnels up the creek lines and cools the vines.
The major creeks of the ridge, from south to north are the Boodjidup, Margaret River, Ellen Brook, Willyabrup Brook and Yallingup Brook.
Later in the region's development, vineyards were planted in the deeper soils of the flood plain of the Vasse and Carbunup Rivers.
These northward flowing streams empty into Geographe Bay and enjoy good exposure to summer radiation.
This is the region known as Jindong but also includes Carbunup and Marybrook. Higher in the catchment of these two streams, at Treeton and Cowaramup, the vineyards still enjoy a strong northerly exposure.
More recently, the southern half of the Margaret River region has had significant areas planted. For the most part, the vineyards lie in the headwaters of the southerly streams that flow to the Blackwood River as it empties into the Southern Ocean at Augusta.
These southern streams are the Chapman, Upper Chapman, McLeod and Glenarty. The 'Southerly Buster' blowing in from the cold Southern Ocean has an influence on these sites.
A summer thermal, this wind starts early in the day and can blow hard until dusk. Dependent upon exposure, it can mean much later ripening.