The Bureau of Meteorology’s interactive weather forecasting chart has added new colours – deep purple and pink – to extend its previous temperature range that had been capped at 50 degrees [122°F].

The Australian government’s new forecasting map now has colors that go up to 54°C [129°F].

It’s been a summer like no other in the history of Australia, where a sprawling heat wave of historical proportions is entering its second week. Monday, January 7, was the hottest day in Australian history, averaged over the entire country, according to the Australian Bureau of Meteorology. The high temperature averaged over Australia was 105°F (40.3°C), eclipsing the previous record of 104°F (40.2°C) set on 21 December 1972. Never before in 103 years of record keeping has a heat wave this intense, wide-spread, and long-lasting affected Australia. The nation’s average high temperature exceeded 102°F (39°C) for five consecutive days January 2 – 6, 2013–the first time that has happened since record keeping began in 1910. Monday’s temperatures extended that string by another day, to six. To put this remarkable streak in perspective, the previous record of four consecutive days with a national average high temperature in excess of 102°F (39°C) has occurred once only (1973), and only two other years have had three such days in a row–1972 and 2002 (thanks go to climate blogger Greg Laden for these stats.) Another brutally hot day is in store for Wednesday, as the high pressure region responsible for the heat wave, centered just south of the coast, will bring clear skies and a northerly flow of air over most of the country.

‘‘ The current heatwave – in terms of its duration, its intensity and its extent – is now unprecedented in our records,’’ the Bureau of Meteorology’s manager of climate monitoring and prediction, David Jones, said.

‘‘Clearly, the climate system is responding to the background warming trend. Everything that happens in the climate system now is taking place on a planet which is a degree hotter than it used to be.’’

As the warming trend increases over coming years, record-breaking heat will become more and more common, Dr Jones said.

‘‘We know that global climate doesn’t respond monotonically – it does go up and down with natural variation. That’s why some years are hotter than others because of a range of factors. But we’re getting many more hot records than we’re getting cold records. That’s not an issue that is explained away by natural variation.’’

According to a peer-reviewed study by the Australian-based Global Carbon Project, global average temperatures are on a trajectory to rise a further four to six degrees [C] by the end of this century, with that rise felt most strongly over land areas. It would be enough to tip Tuesday’s over-40 temperatures over much of mainland Australia very close to 50 degrees in some parts.

“Those of us who spend our days trawling – and contributing to – the scientific literature on climate change are becoming increasingly gloomy about the future of human civilisation,’’ said Liz Hanna, convener of the human health division at the Australian National University’s Climate Change Adaptation Network.

‘‘We are well past the time of niceties, of avoiding the dire nature of what is unfolding, and politely trying not to scare the public. The unparalleled setting of new heat extremes is forcing the continual upwards trending of warming predictions for the future, and the timescale is contracting.’’