The Bureau of Meteorology says large and powerful surf conditions on Sunday and Monday are expected to be hazardous for coastal activities such as rock fishing, swimming and surfing.
On Sunday, rain is forecast for Sydney from late morning, with a possible thunderstorm before midday and possible heavy falls in the late afternoon or early evening.
Winds will be west to southwesterly 35 to 50 km/h, reaching up to 60 km/h near the coast in the late afternoon or early evening, before turning south to southeasterly 25 to 40 km/h in the late evening.
Monday will see a very high chance of showers and southerly winds of 30 to 45 km/h.
Sutherland Shire Council is monitoring the impact of strong winds and swells on Bate Bay beaches, and retaining walls, which were were severely damaged by two east Coast Lows in the space of a fortnight in July.
The Esplanade between Cronulla and North Cronulla beaches remains closed while work continues on assessing and repairing damage in the area.
"Calmer weather conditions [since then] have enabled increased sand deposits across a number of Sutherland Shire beaches, including across remnants of the old Cronulla seawall which was recently exposed due to recent storm activity and heavy swells," a council spokeswoman said.
"Council has been advised that strong winds and swells are predicted to form on Sunday and increase on Monday, which may again cause sand erosion and hazardous surf conditions.
"Council will closely monitor the impact of these predicted weather conditions, monitoring access points to the beaches and barricading areas that pose any potential threat to public safety."
The spokeswoman said the condition of the Prince Street seawall between North Cronulla and Elouera was being monitored.
"Capital funds have been allocated to allow for further improvement works to be conducted during the 2020/2021 financial year," she said.
Surf lifesavers are once again urging people to be cautious along the coastline.
The South Coast is expected to be most affected, with the Bureau of Meteorology, on Saturday, issuing a Hazardous Surf Warning and a Marine Wind Warning for the NSW coast from the Eden Coast to the Illawarra Coast.
Steven Pearce, CEO Surf Life Saving NSW, said a low pressure system was making its way southwest across NSW and is producing high winds, rain and damaging surf.