The Fremantle Doctor (The Fremantle Docker) During summer months it consistently blows from the South-West along the southern half of the west coast, starting between noon and 3 pm. It can penetrate as far inland as 100km, reaching York in the early evening.

In Perth, the capital city of Western Australia, and in FREMANTLE the wind is called the Fremantle Doctor because it brings welcome relief from the summertime high temperatures.

On days when the wind fails, the afternoon temperatures of Perth suburbs are considerably higher, often exceeding 40°C (104°F), although this is also attributable to the influence of a strong easterly wind blowing in hot desert air from the arid interior of the state.

The wind is sometimes called the Fremantle Docker, allegedly because in the days of sail, ships would lie offshore waiting for the afternoon wind to carry them into the Fremantle Dock. This is not to be confused with the Fremantle Dockers, the local Australian Football League team. (See Fremantle Sport)

The Fremantle Doctor
The Fremantle Doctor is strongest in December and January, when the temperature differential between the land and ocean is greatest. In February and March the breeze is not as strong, because the ocean temperature is a bit warmer. Though October and November are not as warm, the ocean temperature is cooler resulting in the sea breeze in these months.

Other months have a weak or non-existent Fremantle Doctor. In the winter months, the land temperature is usually cooler than the ocean temperature, and this sometimes results in the weaker land breeze in the early morning.

When the Fremantle Doctor first arrives it is from the west-south-west (WSW) direction. Later when it is at maximum strength, the direction is usually from the SW or SSW. By the early evening, the direction is from the south. This change in wind direction is due to the Coriolis Effect. Other factors like the prevailing wind of a particular day can also have an effect on the direction. A wind rose showing the different wind directions for Perth can be found at the Bureau of Meteorology's website. [Wikipedia]