NSW RFS back burning continues Sunday

Smoke haze isn't expected to be bad around Sydney when back-burning operations resume across NSW on Sunday morning.

Conditions kept a shroud of smoke over the city as operations began early Saturday in the NSW Blue Mountains, but RFS commissioner Shane Fitzsimmons says there's little chance of that happening Sunday.

The RFS is capitalising on one of the 30 days a year in which they can safely back burn, with vegetation ready and able to be burnt due to recent drier conditions - but winds aren't forecast to be strong enough to cause worry.