Electrifying thunderstorm lights up Sydney sky with 25,000 lighting strikes burning down a house and leaving 5,000 homes without power - and there's more wild weather to come

An historic 132-year-old mansion has caught on fire after a wild thunderstorm swept across Sydney, sparking 25,000 lighting strikes.

Fast-moving storms tore through Greater Sydney, the Central Coast, Hunter Valley and the Illawarra regions on Tuesday night, bringing hail, fallen trees and leaving 21,000 homes without power on the first day of summer.

Power is being restored to 5,000 homes across the city and north of Sydney on Wednesday morning. 

'Work has commenced this morning to restore power to the remaining 5,000 customers impacted by last night’s ferocious storm. All customers will have their power back this afternoon. Thanks for your patience,' Endeavour Energy tweeted.

Forecasters warned the 'pretty remarkable' weather event along Australia's east coast is expected to continue, days after temperatures soared into the 40s along Sydney's coastline.

Firefighters were able to save the Amesbury mansion in Ashfield on Tuesday night. Pictured is the bell tower alight after it was struck by lighting strikes

Stunning footage captured the dramatic moment a bell tower on top of the Amesbury mansion in Ashfield in the Sydney's inner west was ablaze.

Firefighters managed to save the 10 bedroom mansion built in 1888 which first belonged to Australian engineer Norman Selfe and extinguished the raging inferno within 30 minutes. 

The landmark mansion is described as the area's most significant building and was last sold for $3.25million in 2014.

The NSW State Emergency Service received at least 150 calls across the state on Tuesday night as powerful winds brought down trees and powerlines.

Some residents described the sound of hail as similar to glass breaking. 

There were major delays across the Sydney Trains network due to urgent signal equipment repairs caused by lightning strikes at Granville in the city's west.

The Hawkesbury region in Sydney's north-west was one of the hardest hit areas.

'Please stay at least eight metres from fallen power lines,' Ausgrid tweeted.

Fallen trees and powerlines have blocked streets in Richmond in Sydney's north-west

After another warm day where the temperatures soared to 38C in the city's west on Tuesday, Sydney can expect a milder day on Wednesday with a top of 24C before warming up again in coming days to to 32C on Sunday.  

The sweltering heatwave continues in the state's west with another day of 40C plus temperatures and a total fire ban in place for the NSW north-western region.

Bourke was the hottest place in NSW on Tuesday with 47.6C, while Walgett in the north-west hit 46.6C.

Further north, the Queensland heatwave continues with Brisbane to reach the mid 30 as a six-week-old bushfire on Fraser Island off the state's mainland continues to burn.

Elsewhere across Australia, Melburnians are in for a partly cloudy day and a top of 19C, while Adelaide will reach 21C.

It will be a sunny 25C in Canberra wile over in the west, Perth will hit 26C.

Snow is forecast to blast Tasmania's alpine regions on Wednesday with Hobart heading for a top of 18C. 

Around 25,000 lighting strikes were recorded across the habour city on Tuesday night

Lightning is seen during Tuesday's massive storm even as the wild weather battered the coast

'There's some pretty remarkable weather today and during the coming week with heat lingering on and battling a cool change in the southeast and that's causing some severe weather,' Sky News meteorologist Rob Sharpe said.

The extreme weather contrast is nothing new for early summer in Australia and occurs when hot and cold air masses cross over before the wet season begins. 

'At this time of year, we have weather patterns where cold air moves up from the Southern Ocean - which is always still cold at this time of year - and hot air building up over central and northern Australia before the wet season kicks in, and this is a particularly hot air mass for the start of summer,' Weatherzone meteorologist Ben Domensino added.

A large storm cell is seen moving up the East Coast near Wollongong on Tuesday evening

THE WEATHER IN YOUR CITY 

SYDNEY:      

WEDS: Min 20, Max 24. Partly cloudy.

THURS: Min 17, Max 24. Cloudy.

FRI: Min 17, Max 28. Partly cloudy.

MELBOURNE:  

WEDS: Min 12, Max 19. Partly cloudy.

THURS: Min 11, Max 22. Mostly sunny.

FRI: Min 12, Max 23. Mostly sunny.

ADELAIDE:  

WEDS: Min 12, Max 21. Cloud clearing.

THURS: Min 11, Max 25. Sunny.

FRI: Min 12, Max 29. Sunny.

CANBERRA:     

WEDS: Min 12, Max 25. Sunny.

THURS: Min 11, Max 26. Partly cloudy.

FRI: Min 9, Max 28. Sunny.

BRISBANE: 

WEDS: Min 23, Max 34. Hot. Mostly sunny. Possible smoke haze.

THURS: Min 23, Max 29. Cloudy.

FRI: Min 23, Max 32. Partly cloudy.

PERTH:  

WEDS: Min 12, Max 26. Sunny.

THURS: Min 14, Max 31. Sunny.

FRI: Min 15, Max 26. Partly cloudy.

HOBART:  

WEDS: Min 10, Max 18. Possible early shower. Windy.

THURS: Min 10, Max 20. Partly cloudy.

FRI: Min 13, Max 20. Shower or two.

DARWIN:  

WEDS: Min 25, Max 34. Shower or two. Possible storm.

THURS: Min 26, Max 35. Shower or two. Possible storm.

FRI: Min 26, Max 34. Shower or two. Possible storm.

SOURCE: Bureau of Meteorology