The Bureau of Meteorology has released its 2019 annual climate statement, showing 2019 was both the warmest and driest year on record for Australia.
The annual climate statement is the bureau's official summary of the previous year and includes information on temperature, rainfall and significant weather.
Australia's average mean temperature in 2019 was 1.52 degrees Celsius above average, making it the warmest on record since consistent national temperature records began in 1910 and surpassing the previous record in 2013 of 1.33 degrees above average.
Meanwhile, the national average rainfall total in 2019 was 277 mm, the lowest since consistent national records began in 1900. The previous record low was 314 mm set during the Federation drought in 1902.
Bureau of Meteorology head of climate monitoring Karl Braganza said the record warm and dry year was one of the key factors influencing recent and current fire conditions in large parts of the country.
“2019 was consistently warm, but it was book-ended by periods of extreme heat,” Dr Braganza said.
“January last year was the warmest month Australia has ever recorded, while just a few weeks ago in December, we saw the Australia-wide record hottest daily average maximum temperature broken multiple days in a row.
“At the same time, rainfall deficiencies across large parts of eastern Australia have continued to increase, unfortunately exacerbating both drought conditions and the current bushfires.”
Dr Braganza said there were multiple factors influencing Australia's weather patterns in 2019.
«« "Most of this »» He said for most of the year, Australia's climate «« has been »» was "dominated by a very strong positive Indian Ocean Dipole, which acted to both warm and dry Australia's landscape, particularly from around the middle of the year".
“We also saw the influence of a rare Sudden Stratospheric Warming event high above the south pole, which acted to push our weather systems northward and compound the warmer and drier than average conditions over southern Queensland and NSW during spring, amplifying the fire weather.
“The other key factor at play is that Australia's climate has warmed by more than a degree since 1910, which means very warm years like 2019 are now more likely to occur, while the trend in recent decades has been for drier winter and spring seasons in the south.”
Last year also saw some periods of significant rain in northern Queensland and north-west Western Australia.
“In January and February, we saw exceptional rainfall have a major impact on communities in northern Queensland, particularly around Townsville,” Dr Braganza said.
“The floodwaters were so significant they eventually made their way to South Australia, where we saw one of the largest fillings of Kati Thanda-Lake Eyre in many years.”
In recent weeks, some of the key drivers of the recent warm and dry patterns over Australia have eased.
As a result, rainfall for the coming months is expected to be average to below average in the east, while wetter than average conditions are possible for much of WA and SA.
However, temperatures are likely to remain warmer than average over the rest of summer.
“Unfortunately the outlook is not indicating a widespread return to wetter than average conditions over drought and fire-affected parts of eastern Australia,” Dr Braganza said.
“But with the likely return of the monsoon by mid-January for northern Australia, it raises the chances that we could see some periods of higher rainfall move south in the coming months.
“It's important the community remains vigilant to the risk of more heat and fire days this summer, particularly given how dry the country has been over the past 12 months.”
¦ Warmest and driest year for NSW as a whole.
¦ Mean temperature 1.95°C above average, exceeding the previous record from 2018 by almost 0.3°C.
¦ Sydney's mean maximum temperature the warmest on record.
¦ Total rainfall below average in Sydney, despite a wet March, June and September.
¦ Victoria's fifth-warmest year on record overall, with the state's mean temperature 1.05°C above average
¦ Victoria's 10th-driest year on record, with rainfall below average for most of the state, and very much below average in the north and over Gippsland.
¦ Melbourne's mean temperature above average.
¦ One of the driest years on record for central Melbourne.