Sydney haze due to backburning

The haze that has spread across Sydney's skies is a result of hazard reduction burns that have been underway throughout NSW this week.

A smoke haze blanketing Sydney is expected to hover over the city as backburning throughout the state continues during the weekend.

Sydneysiders have been advised of potential smokey conditions for the next couple of days as fire crews work with NSW National Parks and Wildlife Service (NPWS) to take "advantage of the mild and dry weather to complete hazard reduction burns".

NPWS director Metro and Mountains Tom Bagnat said that backburning totalling almost 5000 hectares would be carried out until Sunday.

"These burns are strategically undertaken to increase protection for homes and properties during summer, with the involvement of a number of agencies that include the RFS and FRNSW," he said on Friday.