The tropical regions of Australia, in the north of the country, including the equatorial and sub-tropical zones have high temperatures and high humidity and distinct wet and dry seasons.
In the Australian tropics the wet season10, called the monsoon season, lasts about six months, between November and March. It is hotter than the dry season, with temperatures between 30 and 50 degrees Celsius. This is because of high humidity during the wet, which is caused by large amounts of water in the air. During the wet there is a lot of rain, which frequently causes flooding11.
The dry season lasts about six months, usually between April and October. Temperatures are lower and the skies are generally clearer during the dry season. The average temperature is around 20 degrees Celsius
The 'build up' is the humid time of the year between the wet and dry seasons. It usually lasts for three or four months. Things become quite tense during the 'build up' as people sit and swelter in the humidity while waiting and hoping for the first rains to come. The humidity continues day and night with no respite, so when the rains finally do come everyone enjoys their cooling relief.
Bureau of Meteorology, Maximum temperature12
In the southern capital cities: Sydney, Canberra, Melbourne, Hobart, Adelaide and Perth, defined by the temperate zone, the average temperatures are: summer minimum 16 and summer maximum 26 and winter minimum 6 and winter maximum 14, all in degrees Celsius.
In the sub-tropic and tropical cities the average minimum temperatures are: Brisbane 16 and Darwin 23 with the average maximums: Brisbane 25 and Darwin 32. In the inland city of Alice Springs, surrounded by desert and grassland, the average minimum is 20 and the average maximum is 32.
Since the 1950s, Australian temperatures have, on average, risen by about 1°C with an increase in the frequency of heat waves and a decrease in the numbers of frosts and cold days, except in the regions close to the west and north-west of Sydney.
Since 1900 the sea temperatures have been two degrees warmer13.
2. Indigenous Seasonal Calendars
Indigenous people's knowledge about the weather and their descriptions of the seasons and climatic conditions are recognized today14 by scientists and the Australian Bureau of Meteorology (BOM).
For the Jawoyn people, from around Katherine near south east Arnhem Land in the Northern Territory, six seasons are described15 in the tropical zone in which they live. These descriptions can be useful as they are more detailed in their description and therefore more informative about what weather to be experienced.
Mataranka tropical pool, Northern Territory
- January: Summer (temperate zone), Wet (tropical zone), Jiorrk, the wet season
- February: Summer (temperate zone), Wet(tropical zone) Jiorrk, the wet season
- March: Autumn(temperate zone), Wet(tropical zone) Bungarung, the end of the rains
- April: Autumn(temperate zone), Dry (tropical zone) Bungarung, the end of the rains
- May: Autumn (temperate zone), Dry (tropical zone) Jungalk, the hot start of the dry
- June: Winter (temperate zone), Dry (tropical zone) Jungalk, the hot start of the dry