Brisbane is in for a wet start to the week, with storms likely to hit the city on Monday and rain predicted for the following four days.

In a town regarded as one of the world's hottest, Marble Bar locals are still reminded to take care as the mercury hit 48 degrees Celsius on Monday.

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

Residents in north-eastern NSW advised not to travel as heavy rains from another east coast low lift flood risks all the way down to the Hunter.

Sydneysiders can expect several days of rain-soaked commutes after an early morning downpour ended three weeks of uninterrupted sunshine.

Thunderstorms have rumbled their way across Sydney for the ninth consecutive day, with more thunder and lightning on the horizon throughout Monday morning and into the afternoon.

Sydney's run of balmy weather will take a break as a strong cold front brings a wintry chill to much of the state's south.

Canberrans still wringing themselves out from the wettest June on record shouldn't put away their gumboots just yet.

Temperatures are set to climb towards 40 degrees in coming days in Sydney's west with only cooling sea breezes likely to cap the mercury in the city.

A severe storm is expected to narrowly miss Canberra on Monday afternoon.

Sydneysiders look set for a soggy commute to end the working week, as an intense low pressure system off the coast delivers widespread showers, wind and large and powerful surf conditions to the city.

Unless you've been inside a 200kmh blast of wind it's hard to imagine the tremendous natural force behind it.

Growing winds and driving rain from Hurricane Hermine lashed Florida's northern Gulf Coast on Friday as forecasters warned of "life-threatening" floods.

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.

Temperatures in Canberra reached 38.5 degrees as the region's first heatwave of the year peaked on Wednesday.

The trough that brought a series of storms to Canberra on Saturday is expected to affect the region until Monday.

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

A fierce blast of winter has prompted a severe weather warning for most of southern NSW, including Sydney.

It will snow in the ACT tonight as a cold front moves over the region, the Bureau of Meteorology says.

Sydneysiders can expect more rain to fall tonight before it clears to a cloudy but chilly Monday morning.

The state's second east coast low in as many weeks is likely to bring further heavy rains to north-eastern NSW but largely skirt flood-hit areas around Sydney and the Hunter Valley, meteorologists say.

Prepare for hotter days and a worsening drought - a ''substantial'' El Nino event is underway.

Sydney in for scorching weather on Friday as a slow-moving high-pressure system steers a huge hot air mass formed over Australia's Red Centre to the country's south-east.

Sydney will likely come close to notching its hottest day this late in the summer for 12 years - and there won't be much early relief.