Days more torrential rain is expected to be unleashed on already drenched north Queensland, leading to dangerous flooding and potentially breaking major records.

The weather bureau warned on Monday that (AEDT) a tropical low hanging off the coast of Townsville could linger until Wednesday.

That could dump another 500 millimetres in 24 hours on regions that have already had an astonishing one metre of rainfall over the weekend.

About 1700 homes in the city of Townsville are at risk of inundation and there have been evacuations from so-called “black” zones.

The emergency warnings cover six Townsville suburbs where thousands of residents have been told to leave.

Defence personnel and police door-knocked thousands of homes across the weekend to warn people in at-risk areas to prepare to evacuate.

Homes go under in Ingham, north of Townsville. Photo: Facebook

Meteorologist Jonathan How warned there was “more heavy rain to come as well as dangerous major flooding and there could be historic levels of flooding”.

The Herbert River at Ingham, north of Townsville, could rise to historic levels not seen since 1967. 

There could be 24-hour rainfall totals of 500 millimetres in areas between Ayr and Cardwell, How said. Six-hourly totals could be 160 millimetres.

How said the moist tropical low causing the wild weather was not expected to go far in coming days.

“Into Monday, it’s expected not to move much. So heavy rainfall will continue — even into Wednesday and mid-week,” he said.

“There will be a few breaks but there’s still risk of flooding and flash flooding and major flooding in some areas.”

The extreme weather turned deadly on the weekend when a 63-year-old woman was killed in floodwaters.

Police said the woman was one of six people in a State Emergency Service boat rescuing people in floodwaters when it struck a tree and flipped.

Queensland Premier David Crisafulli warned residents not to be complacent.

“At the moment, there is a real risk and the rain continues and the modelling shows that it may continue for some time,” he said early on Monday.

“We are asking people to heed the warnings and stay connected and above all look out for your mates.”

He said there were 11 swift water rescues on Sunday night.

A tropical low over Townsville is bringing torrential rain and strong winds. Photo: Jerome West

Townsville and surrounds have already had 500-800 millimetres, with more rainfall of up to 500 millimetres in some areas.

Roads are cut, Townsville’s airport is closed and 100 schools have shut.

The Bruce Highway — the state’s major north-south freight and commuter corridor — was closed at Cluden, between Townsville and Ayr and Ingham to Yabula.

Energy Queensland said it turned off the substation supplying power to about 6700 properties around Ingham while the community of Palm Island went dark after a landslide damaged the electricity network.

Townsville’s Ross River in full flow at Black Weir. Photo: Jerome West

Storms smash Vic amid heatwave

Millions of Victorians are in the grips of a three-day heatwave as tired crews try to tame raging fires following a night of wild weather.

Temperatures are expected to hover in the high 30s and low 40s for north-west, west, north, north-east and central parts of Victoria on Monday after a sweltering and stormy end to the weekend.

Severe thunderstorms swept across Geelong and Melbourne on Sunday night, bringing lightning, hail and damaging winds.

Power was cut to more than 38,000 customers across the state with unplanned outages as of 10.45pm Sunday.

But the storms are set to give way to blazing sunshine on Monday, with a forecast top of 39 degrees for Melbourne and Bendigo, 38 degrees for Geelong and 36 for Ballarat.

Meteorologists had predicted overnight minimums to stay in the mid to low 20s, heightening the chance of heat exhaustion.

To beat the heat, people should plan activities during the coolest part of the day, drink plenty of water, wear light and loose-fitting clothing and check on family, friends and neighbours.

“Extreme heat can be a killer,” Premier Jacinta Allan said on Sunday.

“That’s why it’s so important that we look after ourselves and look after each other.”

Most at risk are those older than 65, babies and young children, pregnant women, people with acute and chronic health conditions and socially isolated individuals.

There were also severe heatwave warnings on Monday across the border in Adelaide and the South Australian regions of Riverland, Upper South East, Murraylands, Mount Lofty Ranges, Lower South East and the Mid North.

Sunday’s hot conditions breathed new life into bushfires in the Grampians and Little Desert national parks, burning in Victoria’s west since Australia Day.

Fire Forest Management Victoria sector commander Bec Luppino said the 40-degree heat made life difficult for those on the ground.

“Your body temperature, your core temperature can get pretty warm,” she said.

“It is tough, arduous work. We’re working in extreme heat.

“We can sometimes get so caught up in what we’re doing that we don’t stop and take time to hydrate and refuel ourselves.”

The Little Desert blaze was declared contained but broke away on Sunday afternoon, sparking a warning for people to evacuate the tiny town of Nurcoung.

An emergency warning was issued earlier for the small farming community of Mirranatwa as northerly winds picked up in the Grampians.

Those residents were advised to flee towards Dunkeld and take refuge at the Hamilton Performing Arts Centre or with family and friends outside the danger area.

-with AAP