Bushfires rage across NSW 

Source: ONE NewsBushfires rage in NSW

A lethal combination of soaring temperatures and high winds gave the NSW bushfire season a vicious jolt on Thursday with more than 80 fires raging across the Australian state.

A number of properties have been destroyed and casualties are starting to mount with at least four people badly burnt.

A 60-year-old man suffered burns to 36% of his body battling a blaze that destroyed buildings near Albury, while two others were airlifted to Canberra Hospital with burns caused by a fire at Michelago, near Cooma.

At Londonderry, in Sydney's northwest, several residential streets remain under direct threat from a fast-moving bushfire, the Rural Fire Service (RFS) reported.

The RFS said there were unconfirmed reports of one residential building destroyed in the Londonderry fire, while a number of sheds and outbuildings in the area had also been lost.

Fire authorities said temperatures that soared into the 40s and blustery winds were the trigger.

"That elevation in temperatures and particularly wind has really been problematic for firefighters," RFS Commissioner Shane Fitzsimmons told the Seven Network.

"We have had indications of a house lost at Londonderry - we are still waiting to confirm that.

"Further south in the state we have a very serious fire burning north of Albury affecting places around Gerogery and we've got reports of houses burning in that area as well."

The Ambulance Service of NSW said the 60-year-old man seriously injured at Gerogery had apparently fallen while fighting a fire on his property. He was rushed to Albury Base Hospital.

At Michelago, the Southcare Helicopter picked up two casualties and flew them to Canberra Hospital, while medics attempted to access a third person suffering burns as a 150 hectare blaze threatened three properties.

Three people were treated for dehydration, smoke inhalation and anxiety at Londonderry, the ambulance service said.

More than 200 firefighters are battling fires directly impacting on several streets in Londonderry where the temperatures topped 42 degrees about 2.30pm (AEDT).

"It is a very tense situation," RFS spokesman Alex Chesser told AAP.

"Firefighters are doing everything they can to protect properties in the path of the fire and residents are being urged to follow the bushfire survival plan."

Five aircraft, including an air crane, are battling to protect properties around Nutt, Devlin, Smeeton, Taylor, Londonderry and Hinxman roads in the semi-rural suburb.

Road closures are in place and the RFS has urged people to avoid the Londonderry area.

In southern NSW, several houses are reportedly burning in the area north of Albury around Gerogery and Gerogery West.

The RFS says these outbreaks could get out of control if a predicted southerly wind change occurs, threatening Woomargama, Mullegandra, Mountain Creek and Tabletop.

Properties at Tooma, near Tumbarumba in southwest NSW, are also likely to come under threat on Thursday night.

Aircraft have been waterbombing the region, with fires burning out more than 1,000 hectares of land.

Fire bans remain in place across much of the state until midnight.

Lower temperatures and cooler winds predicted for Friday are hoped to bring relief to firefighters and residents in fire zones across the state.