More than 800 attended NSW emergency departments for sunburn treatment in the last financial year, with the majority being children and young people.
The numbers were a 28 per cent increase on presentations the previous year.
Two-thirds of Australians will be treated for skin cancer during their lifetime and 95 per cent of melanoma and 99 per cent of non-melanoma skin cancers are caused by overexposure to the sun's ultraviolet (UV) rays.
NSW Chief Cancer Officer Tracey O'Brien said high sun exposure in the first 10 years of life more than doubled a person's risk of developing melanoma skin cancer.
"Australia has one of the highest skin cancer rates in the world and protecting our skin from the sun from a very young age, and into adulthood, is key to reducing our risk of skin cancer," Professor O'Brien said.
"When people think of skin cancer risk, they often think of a day at the beach, but in NSW, UV radiation levels are high 10 months of the year which is why its vital people protect their skin all year round, even on cool and cloudy days.
In NSW alone, 8000 people will be diagnosed with skin cancer by the end of 2023.
"Tragically, we'll see over 500 people lose their life to this deadly yet very preventable cancer," Prof O'Brien said.
"We need to do more to protect ourselves from the harmful radiation UV rays from our sunlight."
The NSW government has launched a skin cancer strategy 2023-2030, which will focus on embedding prevention across the public, private and community sector.
It will also seek to improve access to quality shade at work, school, play and public spaces and increase sun safe behaviours.
NSW Health Minister Ryan Park said he would not oversee a rise in skin cancer during his time in government.
"We are seeing time and time again young people, highly skin burnt, presenting to emergency departments or GPs to try and get treatment for something that could have been prevented," he said.
"For 10 months of the year in this country, we have very, very high rates of UV (and) that means that we are in a very vulnerable and dangerous situation."
