The searing end to 2018 for much of Australia will likely make it the third-hottest on record for maximum temperatures with little early relief in sight in the new year, preliminary data from the Bureau of Meteorology shows.

For mean temperatures, 2018 will also come in among the top five, according to bureau meteorologist Skye Tobin. The year was also "very much drier" than average for Australia, particularly in the south-east.

All but one of the country's top 10 hottest years have occurred since 2005, a result "in line with long-term trends resulting from anthropogenic climate change", the bureau said in a summary on 2018's national weather.

Up until the middle of December, more than two-thirds of Australia was recording very much above average daytime temperatures for 2018. Pockets of the nation, such as east Gippsland in Victoria and inland northern NSW, were enduring their hottest year on record for maximums.