Australians wanting to have that tanned skin may well have it this summer season, but still beware as weather forecasters predict the country could be facing more of the sun's radiant glory.

For Thursday, Nov 29, alone, temperature in Adelaide is forecast to hit a top 40 degrees, in what could become the seventh hottest day in a row above 30 degrees for the state in 2012.

Melbourne could experience 38 degrees today or higher, while Mildura a high of 44 degrees. Canberra would sizzle at 33 degrees, Brisbane at 31 degrees. Darwin could reach 34 degrees.

States that could most probably experience cooler temperatures today are Sydney at 28 degrees, Hobart at 27 degrees and Perth at 20 degrees.

People may have to start getting used to hotter days, along with droughts, floods, heatwaves and devastating storms.

"Climate change is taking place before our eyes and will continue to do so," Michel Jarraud, World Meteorological Organisation (WMO) chief, said in a statement.

Meantime, Australians living in NSW have been cautioned to take it easy staying under the sun, especially in the afternoon as a heatwave has been forecast to occur in the coming days and potentially sweep across parts of NSW. Western NSW, western Sydney and the lower Blue Mountains could experience searing temperatures of high 30s over the weekend.

Total fire bans have likewise been put up in South Australia due to the forecast heat that could lead to extreme fire conditions. It has been two years since bans were placed in every district of the state, including metropolitan Adelaide.