Australia smashed its previous annual heat record in 2013, with a summer heatwave and spring hot spell among the outstanding periods of unusual warmth.
The Bureau of Meteorology confirmed that last year was the hottest nationwide in more than a century of standardised records, with mean temperatures 1.2 degrees above the 1961-90 average.
The 12 months easily eclipsed the previous annual record set in 2005, when mean temperatures were 1.03 degrees above average.
Every state and the Northern Territory recorded at least their fourth warmest year by mean temperatures, underscoring the breadth of 2013's unusual heat. By maximums, all but Victoria and Tasmania recorded their hottest years.
Among the cities, Sydney posted daily maximums averaging 23.7 degrees in 2013, well above the previous high in more than 150 years of records, of 23.4 degrees set in both 2004 and 2005, said Blair Trewin, a senior climatologist at the Bureau of Meteorology. Minimum temperatures were the third-highest, at 15.1 degrees, a shade below the 15.2 degrees set in 2007 and 2009.
Melbourne posted its third hottest year, also based on records going back to the 1850s, with maximums averaging 21.5 degrees, shy of 2007's record of 21.8 degrees. The city's minimums averaged 12.2 degrees, second only to 2007's 12.5 degrees.
A heatwave in early January, when the national average maximum temperatures reached 40.3 degrees on January 7, set the country up for a hot year. January was Australia's hottest month on record and December 2012-February 2013 was the hottest summer.
This January has also started with a blast of heat over inland regions, with Moomba in South Australia recording 49.3 degrees on Thursday, while Birdsville in Queenland clocked up 48.6 degrees.
Unusually warm waters around Australia helped keep temperatures well above average in 2013, while many parts of the country recorded their mildest winters on record.
The record year for heat came even though key climate conditions in the Pacific, the so-called El Nino-Southern Oscillation, remained in neutral, as they continue to do. Climate experts say another intense El Nino year, such as in 1998, could challenge even 2013's newly set temperature highs.
Australia's warmth during 2013 extended into spring, with September setting records as the most exceptionally hot month on record. Average maximum temperatures were 3.41 degrees above the long-run average, with South Australia's 5.39 degrees above the norm - a record for any state or territory in any month.
The heat was accompanied by early season bushfires, particularly around Sydney in October, and extensive drought across much of Queensland.
Rainfall nationally averaged 428 millimetres, about 37 millimetres below average, for the year.
Globally, 2013 was the sixth hottest year in records dating back to 1880. No year since 1985 has recorded a below-average global mean temperature reading, and nine of the 10 warmest years have occurred in the past 12 years, the Bureau of Meteorology said.
- Sydney Morning Herald