Because Australia is so large, it has many different climate zones. We identify those zones, and nominate the best time of the year to travel to and through them. These equate to each region's peak tourist season. In a nutshell, the best time to visit northern Australia is during the Dry Season (May to September); the coastal regions of southern Australia are generally year-round destinations.
The Hot Humid Zone includes the coast of the Northern Territory, Western Australia north of Broome, Cape York and the northern part of the Queensland coast above Mackay.
Characteristics: The temperature is high all year round; no frost occurs; average annual lowest temperature is 15 degrees C. It is distinctive for its monsoon or Wet Season and Dry Season, with most rain occurring in the wet season. The wet season is hot and humid with an average January maximum temperature > 30 degrees C. The 'build-up' to the wet season (November) is the least comfortable time of year; temperatures are generally at their highest and humidity is also high, without the benefit of cooling rainfall.
Best time to go: May to September
Characteristics: The narrow but long subtropical zone includes the eastern coastline from Coffs Harbour in northern NSW to Mackay, taking in Brisbane, the Gold, Sunshine and Fraser coasts, and the Whitsundays. A narrow strip of WA coastline between Exmouth and Broome also has a Sub Tropical climate. It is a mild climate with a low winter rainfall and reliable summer rainfall; high humidity from November to March; frosts are rare; average annual lowest temperature 10 degrees C. Warm, humid, wet summer, average January maximum temperature < 30 degrees C.
Best time to go: May to September is the most pleasant. The high humidity and summer rain experienced from November to March can be unpleasant for those not used to it but rarely is it unbearable.
Semi Arid Grassland
Where: Central Australia
Characteristics: Inland Australia has very high summer temperatures; very high evaporation; a dry summer with prolonged drought is common. The semi-arid northern part has a hot, dry summer and mild winter.
Best time to go: May to September is the most pleasant.
Where: Central Australia
Characteristics: Inland Australia has very high summer temperatures; very high evaporation; a dry summer with prolonged drought is common. The more arid southern part has a hot dry summer and cold winter with an average annual lowest temperature of -5 degrees C.
Best time to go: May to September is the most pleasant during the day but expect very cold nights.
The warm temperate zone includes inland Queensland, New South Wales tablelands, the coastal region south of Sydney and north to Coffs Harbour. In WA it is approx. the coastline south of Exmouth to Geraldton and inland to Meekatharra.
Characteristics: Cool winters with light frost, usually non-existent on the coast. The ocean moderates temperature in the coastal zones. The rainfall is reliable year round; average annual lowest temperature 5 degrees C. Warm summer, average January maximum < 30 degrees C. Temperate zones experience the distinct four seasons.
Best time to go: All year round. Avoid winter (July to August) if you don't like cold nights.
Where: The Mediterranean zone includes much of southern coastal Australia from Melbourne, Adelaide through to Perth.
Characteristics: It is shares many of the features of the Warm Temperate zone, except for rainfall which is predominantly in winter with a low summer rainfall. The winter is cool, average annual lowest temperature 5 degrees C. The summer is warm to hot but with a low humidity.
Best time to go: All year round. Avoid summer (December to February) if you don't like warm to hot summers. Wildflower season (June to August in the north; August to October in the south) in WA is recommended.
Cool temperate and Alpine
Where: This zone includes Tasmania, Canberra and the ACT, all high mountain areas including the Granite Belt of SE Queensland, the high areas of the NSW tablelands (Armidale, Glen Innes), the Southern Tablelands of NSW and the high areas of Victoria.
Characteristics: Cool temperate zones experience cold winter temperatures with heavy frosts during the cooler months: spring is a longed-for event. Summers are warm and mild, average annual lowest temperature 0 degrees C to -5 degrees C. Alpine areas experience snow.
Best time to go: Summer (December to February) and Autumn (March to May). Can be cold and wet in winter; Spring (September to November) can be changeable.