Temperatures across Australia's south east have soared today as parts of NSW came close to 50 degrees.

Penrith, in Sydney's west, hit a record-breaking 48.9 degrees just before 4pm according to the Bureau of Meteorology, making it the hottest day on record for the area.

It breaks the previous record of 47.3, set in January, 2018. Then, that was the hottest the suburb had reached since 1939.

This heat map shows Australia is the hottest place on Earth right now with temperatures around 50C in some parts. (Supplied)

Crews battle a grass fire in Batemans Bay on the New South Wales south coast. (9NEWS)

Thankfully, there are no major blazes burning in the region with just a few grass fires which are currently under control by emergency crews.

Canberra has also seen its record broken with the state reaching 43 this afternoon, breaking the previous temperature of 42.2 recorded in 1968.

Earlier today, Nowra, on the New South Wales south coast, reached 33.9 degrees at just 9.40am.

The Bureau of Meteorology did expect Nowra to peak at a staggering 45 degrees Celsius with hot, strong winds forecast.

But the temperature reached a maximum of 40.6 and is now starting to cool.

Wind gusts of up to 45 km/h are due to pick up this evening.

Nowra staging area, brigades coming into for air filter cleaning and quick servicing and daily briefing on the situation to the west and south of Nowra. (Sydney Morning Herald)

Meanwhile, Australia may face a tropical cyclone this weekend at the same time as other states prepare for fires.

Rural Fire Service tankers at Moruya near Batemans Bay, in NSW, on Saturday. The region is bracing for temperatures in the high 40s. (AAP)

The Bureau of Meteorology says there are increasing signs a tropical cyclone will form off the northwest coast of Western Australia.

Forecast models suggest a low pressure system between Australia and Indonesia could develop into a tropical cyclone either tomorrow or on Monday.

"Regardless of whether this low turns into a tropical cyclone, there is a good chance that wind and rain will increase over northern parts of WA early next week," Weatherzone said.

Australia may face a tropical cyclone this weekend at the same time as other states brace for a catastrophic fire danger (Weatherzone)

A forecast map for Tuesday shows a Tropical Cyclone pushing into Western Australia (Weatherzone)

"If a tropical cyclone does form, it may case more severe weather, with heavy rain, damaging winds and a storm surge all possible effects should it near or cross the coast."

Strong wind warnings have already been issued for: Perth Local Waters, Pilbara Coast West, Ningaloo Coast, Gascoyne Coast, Geraldton Coast, Lancelin Coast and Perth Coast.

The next tropical cyclone to form in Australian waters will be named Blake.

Meanwhile, in the south-east of the country millions are bracing for horrendous bushfire conditions.

READ MORE: State of Emergency in NSW and State of Disaster in Victoria

In NSW, temperatures surpassing 40C are set to combine with dry lightning strikes and wind to add to the state's bushfire nightmare.

A number of days of respite are expected to follow.

Today's forecast paints a grim outlook for parts of the state - particularly the South Coast - already battling scores of uncontrolled deadly bushfires as residents flee their homes and holiday-goers cancel plans.

Parts of Australia's southeast coast were recorded as the hottest place on Earth today. (Weatherzone)

In NSW, temperatures surpassing 40C are set to combine with dry lightning strikes and wind to add to the state's bushfire nightmare (AAP)

Heat is set to quickly rise before a change sweeps over the state, Bureau of Meteorology acting NSW manager Jane Golding said.

"In short, we've got a long hot day to get through first with some really dangerous fire dangers," Ms Golding said.

"That cold front bringing that southerly change, we're expecting that not to reach the far south coast ... until late in the day, to move through the Batemans Bay region early evening and come through Sydney about midnight."

The fire danger will reach extreme levels in some areas and the forecasted late cool change is due to bring thunderstorms and lightning.

"The chance of new fires from lightning tomorrow is high," Ms Golding said.

Today's forecast paints a grim outlook for parts of the NSW - particularly the South Coast (Lake Conjola pictured) (AP/AAP)

"The main area we're concerned about is an area stretching right from the South Australian border to the central and southern slopes, western slopes of NSW."

In Victoria, temperatures are expected to creep up today, with parts of Gippsland set to hit 40C and areas of the northeast to reach 45C, before a gusty southerly change is forecast.

Fire-ravaged Mallacoota, where thousands remained stranded on the beach, is expected to reach 40 degrees. The first Navy ship carrying evacuees arrived at Port Hastings on early Saturday and will resupply before heading back to collect more people.

Even after the wind change, the Bureau of Meteorology says dry lightning could strike.

"Don't just be focused on the fires we've got at the moment. Be thinking about where there would be other fires," Victoria's Emergency Management Commissioner Andrew Crisp said.

IN PHOTOS: What the bushfire smoke looks like from NASA satellites

He said it is also possible some current fires could merge, including a blaze in Corryong in the northeast and another in southern NSW.

Between five and 20mm of rain could fall over Victoria's east tomorrow and Monday, but the Bureau of Meteorology says it is unlikely to do much to stop the fires.

Smoke from the East Gippsland fires hung over central Melbourne yesterday, but is expected to be pushed away by wind today (The Age)

Smoke from the East Gippsland fires hung over central Melbourne yesterday, but is expected to be pushed away by wind today.

And milder conditions in South Australia are expected to help with the major fires on Kangaroo Island.

Adelaide had a top temperature of 41C yesterday, ahead of a cool change, but conditions are forecast to be milder over the weekend with tops in the mid-20s.

And milder conditions in South Australia are expected to help with the major fires on Kangaroo Island (9News)