The Education Ministry has warned schools' truancy rates might rise because families have got out of the habit of regular schooling and some will be worried about Covid-19.
In Christchurch, Somerfield School principal Denise Torrey said her staff were preparing to deal with a wide range of behaviour and emotions among their pupils.
"We're going to have everything. We're going to have children who will, like they do on the first day of school, run in the gate excited to see their friends and teachers, we're going to have some children a little bit worried that mum and dad might have to stay at the gate."
Torrey said the school would be drawing on what it learned after the Canterbury earthquakes.
"What we do know from earthquakes is it's a bit of a roller coaster. Everyone will come back, there'll be a bit of adrenaline and then the real world will kick in and for many of our children the real world is going to be unemployment for whānau," she said.
Torrey said children's feelings would depend a lot on how their parents had reacted to the pandemic and the lockdown, and schools needed to reassure parents that returning to school was safe.
"Invariably when that happens, the children will be coming through the gate very happily," Torrey said.
Ōtorohanga College principal Traci Liddall said teachers would have to take things slowly.
"There's definitely some anxiety that we are going to have to be really cognisant of students and teachers. Also they haven't seen their mates for weeks, so we're really going to be taking it from the perspective of like it's the first day of the school year again."
She said teachers would focus on rebuilding relationships and connections with their students.
"You can't teach kids, you can't expect academic improvement if you don't have good relationships."
Liddall said some students would not be back on Monday because they had underlying health problems, and the school would continue to provide online learning for them.
"It is a lot of work, but ultimately the needs of the kids come first."
The Education Ministry last week warned schools that regular attendance had been falling in recent years and the pandemic could prompt attendance rates to plummet further.
Auckland Secondary Principals' Association president and head of Macleans College Steve Hargreaves said his school had been talking to families about the return to school.
"We do know that there is a number who are just a bit worried - are we on top of the virus, what are the preparations the school's got in place, will my child be safe?" he said.
Hargreaves said schools had been doing a lot of work to ensure classrooms are clean and safe.
"We're just one school, but I know this is what's happening everywhere else, we've had all staff in the last two days planning down to the finest detail about 'okay, we're in a technology class, how are we going to clean the tools between uses of students?'"
Hargreaves said schools had sterilised classrooms and equipment, put barriers around reception areas and told students what hygiene requirements they would need to observe.