Canberra and the outer western Sydney suburb of Penrith have broken temperature records that have stood for 80 years.
The mercury climbed to 48.9C in Penrith and 43.6C in Canberra on Saturday afternoon, the hottest temperatures recorded in those areas. The Canberra mark later rose above 44C.
Penrith set a new record for the hottest temperature in the Sydney basin, beating the previous mark of 47.8C recorded in Richmond in 1939. The new mark also made it one of the hottest places in the world on Saturday afternoon.
The previous Canberra record was 42.8C at the now-closed Acton observation site in 1939.
The Bureau of Meteorology said temperatures in both places could continue to climb later on Saturday.