Kate Delaney, aged 23, was last seen at a small dance party in Howes Valley, 60km from Singleton, about 1.45am on Monday, May 20.

When she failed to return home, officers from North Shore Police Area Command were notified and started inquiries.

Police and family hold serious concerns for Kate's welfare as she has not been seen or heard from since.

Officers from Hunter Valley Police District have coordinated a land search of the area.

Kate is described as being of Caucasian appearance, about 170cm to 175cm tall, of thin build, and with brown hair.

She was last seen wearing a red sarong.

She is known to frequent Sydney's north shore.

Police are exploring the possibility that Kate may have left the property on her own accord.

Anyone with information on her whereabouts is urged to contact police immediately.

Contact Crime Stoppers on 1800 333 000 or https://nsw.crimestoppers.com.au

Information is treated in strict confidence.