NSW Minister for Education Sarah Mitchell said this was the largest cohort of students ever recorded.

She stated that about 497,000 primary school students and 318,000 high school students are enrolled so far for 2020, with 71,000 alone starting kindergarten.

"For more than 30 years, student numbers have been relatively stable in public schools across the state, but now, NSW is facing the first major increase in the school-aged population since the Baby Boom of the 1950s," Ms Mitchell said.

"In 2020, we'll see a once-in-a-generation spike in school enrolments, so it is more important than ever to ensure that as a government, we continue to invest in world class learning facilities."

These figures can also be seen across the Illawarra.

The Department of Education expects to see about 42,880 students attending public schools in the Illawarra region in 2020.

There are projected to be 26,397 primary school students and 16,486 high school students in 2020.

There will also be at least 839 new teachers and 49 new principals across NSW in 2020.

Ms Mitchell said the government needs to continue preparing for growing enrolments over the coming years, with more than 130,000 extra students expected to be in NSW public schools by 2036.

With most students, including those in bushfire affected communities, set to start school on Wednesday, there will be a greater focus on mental health support for students and staff in the wake of the recent devastation.

Ms Mitchell said the NSW Government will work directly with principals and their school communities to ensure there is tailored short and long term support available to best meet the needs of students.

"So far, we've identified 113 schools where increased counselling services will be rolled out, 77 of which will need intensive support that we'll deliver in consultation with the school communities," she said.

Meantime on Tuesday NSW Teachers Federation deputy president Henry Rajendra and senior vice president Amber Flohm will be visiting Kangaroo Valley, Bundanoon and Hill Top.

They will visit the fire affected communities in the Southern Highlands to lend support to teachers and principals and to ensure the needs of fire affected schools and communities are being met.

Mr Rajendra said bushfire damaged schools and local communities in parts of NSW devastated by fires will need enormous support to get back to normal.

"Going back to school this year will be a difficult and emotional time for children, teachers and parents and the NSW Teachers Federation wants to help wherever we can to make sure schools can get back to giving our kids the best possible education," he said.

"We are traveling to the bushfire affected schools to listen and learn because we want to make sure everything possible is being done to deal with the emotional, psychological physical and financial distress caused by this devastation."

To assist its members the NSW Teachers Federation has doubled payments available to teachers under the union's Emergency Relief Fund to support them to purchase teaching resources lost in the bushfires and not covered by insurance.

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Members can apply for payments of up to $1000 for replacement of teaching resources. This is being applied retrospectively to September when the bush fires started wreaking havoc in communities across NSW.

Members suffering financial hardship because of the fires can also apply for an exemption of up to six months from their membership fees to the union.