PART I - CLIMATE TYPES

What do the maps show?

These climate classification maps show three different methods of classifying the climate of the Australian mainland based on three different classification schemes - temperature/humidity, vegetation (Köppen) and seasonal rainfall. Different methods of classification are used depending on the intended use of the output. For example, if you are designing a building, it would be helpful to classify climate based on temperature and humidity in order to get a better understanding of likely air conditioning requirements for the building.

Temperature/humidity zones

The temperature and humidity zones map shows the climate of Australia classified according to temperature and humidity properties across the country. These maps are based on temperature and humidity data collected over the period 1961 to 1990.

This method of classification identifies six key zones across Australia, based on a set of definitions relating to summer and winter conditions:

• Hot humid summer

• Warm humid summer

• Hot dry summer, mild winter

• Hot dry summer, cold winter

• Warm summer, cold winter

• Mild/warm summer, cold winter

The distribution of these six zones can be compared to the maps for temperature and relative humidity with "hot humid summer" identified for areas of northern Australia, through to "mild/warm summer, cold winter" identified in Tasmania and alpine areas.

Köppen maps

The Köppen classification maps show six major groups and 27 sub-groups of climate zones across Australia. These climate zones are defined with the climatic limits of native vegetation in mind. This method of classification is based on the concept that native vegetation is the best expression of climate in an area.

The six major classes are identified predominantly on native vegetation type, with the additional sub-groups taking into consideration seasonal distribution of temperature and precipitation:

• Equatorial

• Tropical

• Subtropical

• Desert

• Grassland

• Temperate

• Seasonal rainfall

The seasonal rainfall maps use the differences between summer and winter rainfall across Australia to identify six major climate zones. These maps use the median annual rainfall (based on the 100 year period from 1900 to 1999) and seasonal incidence (the ratio of the median rainfall over the period November to April to the period May to October) to identify these six major zones. Specific numerical rainfall thresholds are used to identify 16 sub-groups.

• Summer dominant

• Summer

• Uniform

• Winter

• Winter dominant

• Arid

These six classification groups identify the season of highest rainfall in each area, and are similar in distribution to the annual and monthly rainfall maps.