The Bureau of ¼öÁö¿ë´ÞÀÌ»ç Meteorology (Bom) said "extensive" heat on Tuesday Àϻ꼱¸Æ÷ÀåÀÌ»ç tipped the mercury past the previous record of 40.3C set on 7 January 2013.
Taking the average of °ºÏÆ÷ÀåÀÌ»ç maximum temperatures across the country is the most accurate measure of a heatwave.
Forecasters had predicted the most ´ä·Ê¶±=´ä·Êǰ ´ä·Ê¶± Çà»ç¶± ±îÄ¡¶± intense heat would come later in the week, meaning the record could be broken again.
As hundreds of fires rage, Prime Minister Scott Morrison has been criticised for his response to the natural disasters and his government's climate policies.