The hot days in Sydney and Melbourne this week are 8-10 degrees warmer than usual for early spring, while Septembers are warming in south-eastern Australia even faster than the rest of the year.

The highs of 29 degrees in Sydney on Tuesday and 24 degrees in Melbourne on Monday come as the landmark climate risk assessment released on Monday warned historical data was no longer a reliable guide to future risk.

More rain remains expected throughout spring as the Indian Ocean Dipole officially turned negative, while a La Nina event is likely – in part because of change in the way it is measured.

Qian Zhou, a climatologist at the Bureau of Meteorology, said a cold front was bringing cold, unsettled weather to the Southern Ocean, while forcing warmer weather on the other side of it.

“In fr

See Full Page