However, Auckland and Northland will stay in level 4 for now.
Northland is likely to drop a level before Auckland does.
Te Tai Tokerau Principals' Association president Pat Newman wasn't surprised Northland was staying locked down, after seeing the heat map showing how many close contacts had driven up to Northland.
"I was of two minds. One was I think all of us have had enough of lockdown, but all of us also want to be as safe as possible. So we're sort of caught in a bind. I would rather we took the cautious approach than the hundreds that are dying overseas being repeated here."
Level 3 was "a pain in the butt, to be honest", he said.
"We're only open for those who have no choice, emergency workers etc, and they are probably catered for now."
Newman is principal of Hora Hora School in Whangārei. Last time they were in level 3, six teachers were on duty as the school was expecting 30 to 40 children, but only six turned up.
"Te Tai Tokerau is quite different to the city. There are lots of extended families, lots of aunties, uncles, nanas, koros that step in at a time like this and pick up the slack."
Lesley Lomas, president of the Waikato Principals Association, was happy to have Monday and Tuesday to get ready for level 3 learning bubbles.
Principals would have time to survey parents and see whose children would be attending under level 3, before preparing their sites and staff.
Lomas believed her staff at Aberdeen School in Hamilton were feeling okay about opening up, given they were following the health advice.
But level 3 had its challenges, with a combination of learning on site and at home. It was very hard to anticipate who would be coming back to school, she said. She would be awaiting further guidance tonight from the Ministry of Education, and would be sharing it with parents.
Last night the ministry told schools the Government had taken a "health-led, precautionary approach".
Secretary of Education Iona Holsted wrote that she had heard many staff were feeling "uncomfortable or anxious about returning to the classroom".
"It's important to remember that throughout this pandemic the Government has taken a health-led, precautionary approach, so that if we move down alert levels it will only be if it is safe to do so and the settings will support good health and safe practice," she said.
Last year few children attended school in alert level 3 but that could be different this time, in part because rural parents would be particularly busy with calving and lambing season and could not supervise their children's learning, Holsted wrote.
In semi-rural Taranaki, Ōmata School principal Karen Brisco was pleased to be moving down alert levels - with time to prepare.
"We still have to provide all the online learning, our staff are having to do that as well as being onsite so it's a double-do. It's going to take a couple of days so thank goodness we have Monday and Tuesday. Hopefully we'll be allowed on site to set the school up."
Brisco, who is on the NZ Principals Federation Rural Matters team, said many rural families were essential workers in level 4, including farm workers.
"So they're juggling home learning. It will have been quite challenging for them and some may wish to send their children back."
Some teachers had already volunteered to return to work for level 3.
Jane Corcoran, principal of Brunswick School in Whanganui, said providing education was "extremely challenging" in both levels 3 and 4.
The move to alert level 3 would be "no easy task".
"Some schools may be extremely short-staffed, particularly small schools. Principals will need to take a common-sense and practical approach to solving these problems in their own school context. It is a difficult situation and we can only do our best."
Corcoran, who sits on the Rural Educators Reference Group, said more support was also needed to address the ongoing issue of rural internet connectivity and high usage costs.