A fire behind properties on Sydney’s Northern Beaches has been downgraded.

Firefighters backburned overnight Saturday as conditions that fanned a large bushfire eased.

The NSW Rural Fire Service said an 80-hectare blaze was burning eastward between Cromer Heights and Oxford Falls on Saturday.

Residents were warned to monitor conditions in case the situation changed.

The service had issued an emergency warning at 3pm AEST on Saturday, telling people on Pinduro Place, Jersey Place, Maybrook Avenue, Kirrang St and Lady Penryhn Drive in the Cromer Heights area they were at risk.

The fire has since been downgraded to “monitor conditions” as backburning operations began behind properties near Oxford Falls Rd, Lady Penrhyn Drive, Willandra Drive, Maybrook Avenue and Pinduro Place.

Firefighters and waterbombing aircraft worked to slow its spread as the wind and temperature dropped.

The fire service warned residents they would see more smoke as a result of the backburning.

Willandra Rd will stay closed between McIntosh Rd and Little Willandra Rd.

There were no reports of injuries or damage.