The Bureau of Meteorology has issued a severe thunderstorm warning for parts of Sydney.

Parts of Canberra have received more than the city's June average rainfall in less than two days with more rain on the way.

A broad and unpredictable trough stretching across south-east Australia could inundate Canberra with a month's worth of rain this weekend.

A "strangely warm southerly" is sweeping across Sydney today with little relief from the heat at beaches in NSW and Queensland because of Cyclone Winston causing large, dangerous and powerful surf.

The impacts of the monster El Nino in the Pacific are likely to intensify across much of Australia, including worsening drought and an elevated bushfire threat, after conditions that were nullifying its effects suddenly retreated.

Destruction of more than 200,000 hectares of threatened species habitat has been approved by the federal government in the past decade, a report shows.

Fires breached containment lines in two NSW locations on Sunday morning as temperatures climbed above 35 degrees in parts of the state and Sydney.

Winter's grip will finally feel like it's loosened amid a "heat spike" this weekend - even if that season's squeeze was not a very tight one.

Hundreds of homes have been evacuated in southern California as heavy rains and wind lash the drought-stricken area.

Santa looks set to bring Melburnians a mild and mostly sunny Christmas Day.