Sydneysiders will be leaving their winter woolies at home on Sunday to welcome what is expected to be the warmest July day on record.

However, many residents will need to take care if heading outdoors as the RFS has a number of hazard reduction burns planned for Sunday.

Boardriders enjoy unseasonably balmy conditions over the weekend. Credit:James Alcock

Much of Sydney was blanketed in a thick covering of smoke on Saturday and while stronger winds are likely to prevent a similar situation on Sunday, the RFS is urging those with respiratory conditions to take care.

"We advise residents to keep doors and windows closed, remove washing from clotheslines, ensure pets have a protected area and, for those on the road, we advise you to slow down and turn your headlights on should smoke reduce visibility." An RFS spokesperson said.