Thousands of day-trippers will head to Illawarra beaches today as the mercury rises to 33 degrees in Wollongong and a sweltering 37 degrees in Nowra.

But some say the new menace for beachgoers and swimmers is not sunburn, but shark attack.

Others, such as one lifeguard who spoke to the Mercury yesterday, say the shark fear is pure hysteria.

"There's sharks out here all the time but now people are getting all excited," the lifeguard said.

"They see a little splash in the water that looks like a fin and they think it's a shark."

Thirroul lifeguard Jake Spooner was more willing to indulge the shark menace.

Mr Spooner said a 5m white pointer was pulled out of the shark net at Thirroul last month.

He also said that in his nine years as a lifeguard sharks had been a regular visitor at Illawarra beaches.

"I saw a shark out there two months ago - it was pretty big, so I came back in, but most surfers don't bother," Mr Spooner said.

Penrith's Andrew and Renelle Ringrose and their children, Anaiya, 7, and Lexie, 4, were staying well away from deeper surf at Thirroul Beach yesterday.

"We don't go anywhere deep because of the sharks," Mr Ringrose said. "There are heaps of them. I used to surf but not anymore."

Mr Ringrose has a theory as to why sharks appear to be making more regular appearances on the coastline.

"I don't think there is enough fish left in the ocean and there is a better feed closer to the coastline," he said. "The sharks are starting to evolve."

But Jamberoo father Terry Kofod, a regular visitor to Thirroul Beach, laughed off suggestions he should stay away from the water.

"I am meaner than any white pointer," Mr Kofod joked. "There is nothing to be scared of."