The Bureau of Meteorology has issued a hazardous surf warning to affect the northern NSW coast including the Far North Coast, North Coast and Mid North Coast.

The large easterly swell combined with strong winds, means most beaches and rock platforms in these regions will likely see treacherous conditions continue through the week.

Surf Life Saving NSW advises the public to take caution if visiting the coast this week and only swim at a patrolled location between the red and yellow flags.

Surf Life Saving NSW CEO Steven Pearce says it's important for people to heed coastal safety warnings and check local conditions before heading to the beach.

"At this time of year, only 12 beaches are patrolled in NSW," said Pearce. "It's vitally important that beach-goers consider the dangers associated with coastal activities in hazardous surf. By overestimating your ability in the water or on rock platforms, you're not only compromising the safety of yourself but also our lifeguards and emergency services."

Lifeguard Patrolled Beaches in Winter

Visit beachsafe.org.au or download the Beachsafe App, to find patrolled locations and up-to-date beach conditions.

Since 1 July 2018, 40 people have drowned on the NSW coastline.