She was subsequently taken to hospital as a precaution: Hunter Valley Police District Commander Superintendent Chad Gillies

POLICE have found missing Sydney woman Kate Delaney alive at a property in the Hunter following grave concerns for her welfare.

Hunter Valley Police District Commander Superintendent Chad Gillies said the 23-year-old had been located on the Howes Valley property, 60km from Singleton, on Tuesday morning.

He added Ms Delaney was also assessed at the scene.

"At about 11.30 this morning, PolAir located Kate Delaney safe and well about 2.5km from where she was last seen at the tent site," he said.

"She was subsequently taken to [Singleton] hospital as a precaution and my information is was suffering mild hypothermia or mild exposure."

Ms Delaney, from Roseville in Sydney's Upper North Shore, was reported missing on Monday night.

She was last seen at the Howes Valley property, where an organised dance party was taking place, just before 2am on Monday.

Police held serious concerns for her safety because she disappeared without personal belongings including her mobile phone and wallet.

Investigators launched a thorough search of the property on Tuesday morning, including PolAir, SES, police dog squad and trail bike officers.

Investigators were due to make a public appeal for information about Ms Delaney's whereabouts at 1pm but thankfully weren't required to.

Superintendent Gillies did, however, urge people to make emergency services aware of large scale parties, even if it's a private event.

"When you host such a party on a remote property and you don't notify the authorities, especially the police and other emergency service workers, you leave yourself open to this sort of thing," he said.