Australian Weather Calendar: June 2018

June photograph by Andrew Thomas

With a cold and frosty morning forecast for 23 July 2014, Andrew Thomas decided to watch the sunrise from Mount Buninyong in western Victoria. A ridge of high pressure brought clear, cold and still conditions, and the rising sun's rays cast long shadows through patches of fog that had formed overnight.

On clear and still nights the earth loses heat via radiation and cools, which in turn cools the layer of air just above it. When there's enough water vapour in the cooled air, the water condenses into tiny droplets of liquid suspended in the air. This fog generally begins to clear after sunrise, as the sun heats the air and evaporates the water droplets.