Extract from ABC News
The Bureau of Meteorology (BOM) has just finished crunching last month's numbers and confirmed it was Australia's hottest November on record for maximum, minimum and mean temperatures.
It was also the country's hottest spring on record for mean and minimum temperatures.
Key points:
- Australia has just broken the record for its warmest November on record
- It was also our warmest spring for minimum and mean temperatures
- Spring's rainfall was well below the records but significantly greater than last year
November's maximums came in at 2.9C above the 1961-90 average, surpassing the 2.4C mark set in November 2014.
The national minimums were at 2.04C above the average and means at 2.47C.
It wasn't just the past few days that were hot — spring overall saw Australia's mean and minimum temperatures reach the warmest on record at 2.03C and 1.91C above the average, respectively.
Spring's maximum temperatures were only the fifth warmest on record at 2.15C above the 1961-90 average.
Rainfall near average for spring
Nationally, spring rainfall was 8 per cent below average and close to average for most of the country, according to BOM senior climatologist Blair Trewin.
But parts of eastern Queensland, north-east New South Wales and western Tasmania were drier than average.
Outback South Australia and far south-west New South Wales, however, had above-average rainfall.
November was particularly dry for the eastern states but wet in the west.
Many regions are still in drought, while for others this year has been a real turnaround.
Good winter rain in the south means farmers are on track to produce the second biggest grain crop ever, according the latest update from the Australian Bureau of Agricultural Resource Economics and Sciences (ABARES).
The dry window over the past few weeks has been exactly what many farmers needed to get their crop out.
How could it be hotter than last year?
Last spring was extremely dry, the driest on record.
Dr Trewin said when it was extremely dry, there were very hot days but also very cool nights.
So we may remember the hot spring days last year — which were definitely hotter than this year — but last year's cool nights drew the average down.
"This year the real standout has been the warm nights," Dr Trewin said.
Beyond the extremely dry conditions, one contributor to last year's fires was the strongly negative Southern Annular Mode (SAM).
SAM's westerlies brought hot air from central Australia down over the east coast and contributed to the horror fire weather.
A year later, the SAM has been in neutral, making these extreme conditions less likely.
Wasn't La Niña going to make things wet and cool?
Dr Trewin said the climate driver was still there but the rainfall was taking its time to arrive.
He said while some La Niña years like 2010 brought heavy rain early, other years took longer to have their effect on Australia.
This year was looking a bit like 1988, Dr Trewin said — 1988 had a strong La Niña but also had a very hot spring before the rain kicked in, making for an extremely wet first half of 1989.
Spring was also expected to be wetter than average, but short-term climate drivers have gotten in the way in recent weeks and prevented the La Niña from bringing about the expected wetter conditions.
Then there is the climate influence.
April-to-October rainfall has been on a downward trend over southern Australia for the past few decades.
Australia's climate has also warmed on average 1.44C (plus or minus 0.24C) since 1910, as outlined in the most recent BOM and CSIRO State of the Climate report.
What's on the cards this summer?
The outlook for the coming months indicates temperatures could be below average in the centre and above-average rainfall is likely for most of the country, but of course it doesn't count until it hits the ground.
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