The BoM has released its climate statement for Australia in December 2023, and it was the nation's hottest fourth-hottest December on record, in records going back to 1910.

• The national area-average mean temperature for December was 1.6°C above the long-term average
• Maximum temps were 1.92°C warmer than usual nationwide
• Minimum temperatures were 1.27°C above the long-term-average nationwide

Warm overall, but not everywhere

It might seem unusual to residents of places like Melbourne or Adelaide that Australia as a whole was so warm in December.

• For example the Adelaide average December maximum in 2023 was just 25.5°C compared to the long-term average of 26.9°C. Minimums were also lower than usual
• Melbourne, too, was down on usual, with an average max of 23.8°C in December 2023 which was lower than the long-term average of 24.2°C

The chart below paints the full picture. It shows that across Australia, temperatures were significantly above average in December 2023 in all but a few relatively small portions of the country.

Image: The anomaly means the difference above or below the long-term average Source: BoM.

Adelaide and most of the SA coastline were in the cool zone due to unseasonable weather systems like the cold front on December 8 and 9 which brought particularly heavy rain to SA, with more than 100 mm recorded at some stations.

Speaking of rain, the biggest rain story of December was obviously the north Queensland flooding in the wake of Tropical Cyclone Jasper, which delivered some phenomenally heavy daily rainfalls which you can read about in our story on the Australian weather extremes of 2023.

But despite that deluge and the SA soaking, rainfall for Australia as a whole was 1.9% below the long-term average in December 2023. That's best illustrated by the chart below.

Image: There was slightly more red than blue. Source: BoM.

The rain in South Australia and far north Queensland shows up clearly, but it was offset in terms of the national average by significant rainfall deficits elsewhere, especially across large parts of WA and the NT.

For the record, there was a margin of 51.8 degrees between Australia's hottest and coldest locations for the month.

• The coldest Aussie spot in Dec 2023 was -2.3°C at Butlers Gorge in Tasmania on the 10th of December.
• The hottest Aussie spot in Dec 2023 was 49.5°C at Roebourne in Western Australia on the very last afternoon of the year. We wrote about the deep heat trough sitting over WA's Pilbara region that caused the extreme heat in this story.