Rainfall deficiencies have affected most of the New South Wales, Queensland and South Australian parts of the Murray–Darling Basin since the start of 2017. These longer-term deficiencies extend to parts of the New South Wales coast, particularly in the Hunter and Illawarra districts, and to much of the eastern half of South Australia from Adelaide northwards. The deficiencies have been most extreme in the northern Murray–Darling Basin, especially in the northern half of New South Wales, where areas of lowest on record rainfall extend from the Great Dividing Range west as far as Dubbo and Walgett. Some of the largest rainfall deficiencies have occurred in the upper catchments of some of the major tributaries of the Darling, including the Macquarie, the Namoi–Peel, and the Border Rivers.

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When compared to other 32-month periods commencing in January, the 32 months from January 2017 to August 2019 has been the driest on record averaged over the Murray–Darling Basin (34% below the 1961–1990 average), as well as over the northern Murray–Darling Basin (40% below average) and for the state of New South Wales (34% below average). All three regions have also been the driest on record for the 20 months from January 2018 to August 2019, whilst the 26 months from July 2017 to August 2019 rank second in all three regions; only the 1900–02 peak of the Federation Drought has been drier. The last 32 and 20 months have also been the driest on record averaged over the Border Rivers, Macquarie–Bogan, Namoi, Gwydir, and Castlereagh catchments, with the last 20 months also the driest on record for the Moonie, Condamine-Culgoa, and Lower Murray catchments.

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Another area of longer-term rainfall deficiencies affects Gippsland, in eastern Victoria, and the east coast of Tasmania. Both the West Gippsland and East Gippsland districts have had their driest 32 months on record, with a substantial area of record low rainfall in central Gippsland centred on Sale and Bairnsdale.

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The dry conditions of the last three years have been particularly acute during the cool season, which is important in many regions for generating runoff. Rainfall for the period from April to September was less than 50% of average in both 2017 and 2018 in 14 of the 30 rainfall districts of New South Wales. In 13 of these 14 districts, rainfall from April–August 2019 was also less than 50% of average. The Central Western Plains (North), which encompasses Nyngan, Trangie, Gilgandra and Coonamble, has had less than one-third of its average cool-season rainfall in all three years.