Australia getting wetter

Since 1910, annual total rainfall has risen by about 15 percent in New South Wales, South Australia, Victoria and the Northern Territory, with little change in the other states. South-west Western Australia has become 25% drier in winter.

The average number of rainy days in Australia has gone up by 10% during the 85-year period studied. The Northern Territory and New South Wales have experienced the greatest increase in rainy days, while Tasmania and south-west Western Australia now has fewer rainy days than in the past.

The changes in rainfall from 1910 to 1995 have not been steady from decade to decade. Following a run of wet La Niña years from 1973 to 1975, there has been a tendency for more El Niños than La Niñas up to 1995.

El Niños are normally associated with relatively dry conditions in Australia. However, since 1975 annual rainfall has not changed much in NSW and Victoria, declined then recovered after 1990 in Western Australia, South Australia and the Northern Territory, and fallen steadily in Queensland and Tasmania.

CSIRO has launched a website containing Australia’s rainfall information from 1910 to 1995, averaged for each State and Territory. For every State and Territory, and for south-west Western Australia, there are graphs showing annual and seasonal total rainfall, rain days and heavy rainfall – 135 graphs containing more than 11,000 statistics.