Sydney's smokey city views to continue

Smoke has blanketed parts of Sydney as fire authorities make use of the favourable weather for bushfire season preparation.

Rural Fire Service (RFS) volunteers were on the ground throughout the city's outskirts - including The Hills, Blue Mountains and North Shore districts - on Saturday carrying out hazard reduction burns.

Smoke from the controlled fires was visible across the suburbs and in some places obscured the view of the city.

Sydney can expect similar conditions on Sunday with more hazard reductions planned.

The NSW Environment Office has advised vulnerable people - including children, the elderly and people with heart and lung disease - to reconsider outdoor activities on Sunday.

The air quality is forecasted to be fair.

Authorities warned last month NSW was at the above average risk heading into this year's fire season despite recent rainfall.

The hot, dry effects of El Nino are expected to make conditions even worse than those experienced in the devastating 2013-14 season, with the dire prediction placing authorities on high alert.