Australia swelters through its hottest month on record, with January mean temperature exceeding 30C

It's official: January 2019 was Australia's hottest-ever month on record going all the way back to 1910, according to the monthly climate review released by the Bureau of Meteorology (BOM).

It followed the hottest December on record for Australia — and there is no relief in sight for the months ahead.

January was a truly record-breaking month across several fronts: the highest minimum, the highest maximum and the highest mean temperatures for Australia as a whole.

The highest overnight minimum on record was broken multiple times with Wanaaring (Barrona Downs) in NSW currently holding the title at 36.6 degrees Celsius.

The mean temperature for January averaged across the country exceeded 30C — the first time this had occurred in any month, the BOM said.

The report also highlighted record long runs of consecutive hot days:

Birdsville (Qld) had 10 consecutive days over 45C
Alice Springs airport (NT) had 16 days in a row above 42C
Cloncurry (Qld) had 43 consecutive days over 40C — a state record for Queensland
Camooweal (Qld) had 40 consecutive days over 40C
Walungurru (NT) had 27 consecutive days above 40C
Bourke airport (NSW) had 21 consecutive days above 40C — a state record for New South Wales
Rainfall was also below average for most areas but a monsoon trough brought some significant totals to northern Queensland late in the month.

Here is how the different states felt the heat
South Australia experienced its driest January since 2013.

And Adelaide had one of the city's hottest Januaries on record, with maximum temperatures the highest for at least 10 years.

For the first time since 1957, the BOM's Adelaide city site recorded zero rainfall for the month.

Western Australia had one of its hottest Januaries on record, but temperatures were cooler than average in parts of the west coast and south-west.

Rainfall for the state was below average and the month was the driest since 2005.

While most of WA was suffering in the heat, Perth recorded its coolest January in more than a decade and rainfall was about average.

New South Wales recorded its hottest January on record for mean, maximum, and minimum temperatures.

The north-east of the state also experienced one of its driest Januaries on record.

Sydney had one of its warmest Januaries on record, with average rainfall.

Victoria also set a new record for January heat.

Its rainfall was below average, with most of the state receiving less than 20 per cent of the month's average.

Melbourne was exceptionally warm, with some sites recording their highest ever January temperatures. The city also had one of the 10 driest Januaries on record.

The ACT also had its hottest January ever. The BOM's Canberra airport site had a record run of four days above 40C.

The Northern Territory recorded its hottest January and the delayed onset of the monsoon contributed to the Territory receiving less than half its average January rainfall.

Darwin had one of its warmest Januaries on record while rainfall was also below average.

Queensland similarly had its hottest January and a monsoon low brought heavy rainfall to parts of the state.

Brisbane was very warm, while rainfall was very low at about 20 per cent of the January average.

Tasmania had its hottest and driest January on record, as did Hobart.

Why so hot?
The predicted El Nino did not eventuate this summer but even without the climate driver we usually associate with hot conditions the temperatures soared.

BOM senior climatologist Andrew Watkins said there were a few factors at play in the unprecedented heat.

"We saw heatwave conditions affect large parts of the country through most of the month, with records broken for both duration and also individual daily extremes," Dr Watkins said.

"The main contributor to this heat was a persistent high-pressure system in the Tasman sea which was blocking any cold fronts and cooler air from impacting the south of the country.

"The warming trend, which has seen Australian temperatures increase by more than one degree in the last 100 years, also contributed to the unusually warm conditions."