Auckland principals are unsure how much the lockdown has set back children's formal learning.
They say based on last year's experience they will need to run catch-up lessons for some or all of their students once classes resume.
But they warn that they will have less classroom time than they did last year for that catch-up learning.
Schools had completed nearly three-and-a-half weeks of the 10-week third school term when the lockdown was introduced, and Auckland schools are worried they will have little if any classroom time before the term ends on 1 October.
Testing found writing was the one area in which children's achievement slumped following last year's lockdowns and did not bounce back by the end of the year.
Auckland dad Marcus Reynolds said writing certainly seemed to be the hardest thing to work on with his two primary school-aged boys.
"You can dedicate time and actually sit down and work through a maths problem with them or something like that, but when it comes to writing it's the writing piece that they need that motivation, that interactivity for," he said.
"As a parent you can't really sit down and sit next to your child while they write a story because it probably puts them off more than anything else."
Auckland's Beach Haven School principal Stephanie Thompson noticed a downturn in achievement following last year's national lockdown and she was expecting the same effect this time around.
She said the school would probably have to institute accelerated classes to help children catch up after the current lockdown, which was the third to hit Auckland schools this year.
"It's probably too early to say what will happen with yet another lockdown but this is our second round here this year so I guess what that means for us back at school in when our students are back on site we'll be putting those acceleration programmes back on site so we can keep the pedal down," she said.
Thompson said accelerated classes required extra teachers and teacher aides and the Education Ministry should stump up funding to help.
The picture for secondary schools was slightly different.
NCEA pass rates would have fallen by a few percentage points last year if the government had not introduced measures such as extra credits.
However this year, teenagers have completed more internal assessments than they had at the same time last year.
Year 13 student Lyric Te Ao from Papatoetoe High School in Auckland has no doubt two years of lockdowns have disrupted her learning.
"It is different for every single student. I know a lot of people actually do a lot better when they're at home but from personal experience over the past years, it's definitely taken a toll on my academics. I could have achieved a lot more if there were no lockdowns or a lot less lockdowns," she said.
The school's principal Vaughan Couillault said his students were definitely worse off than last year because their school had its own Covid-19 lockdowns before the current level 4 closure began.
"We were already 13 days out and so my school would have had 32 days by the 13th of September which is about 17 percent of the school year lost to lockdown," he said.
Couillault said without changes to the NCEA his students' would have been significantly disadvantaged.
He said the current shut down had occurred later than last year's and that was not good.
"We haven't got as much time to catch up and I feel particularly for the students who are doing portfolio-based pieces of work," he said.
Glenfield College principal Paul McKinley said the effect of two years of lockdowns appeared to be most pronounced in this year's Year 11 students.
"They've had interrupted 2020, hit level 1 in 2021 and I think that's the group that's been most hit by Covid," he said.
"There's a combination of interrupted learning in 2020 so perhaps a little bit behind ... playing catch-up so to speak, and getting that motivation factor back up."
He said some Year 11s were dubious about whether their work was worth the effort given there could be a lockdown, whereas Year 12 and 13 students were more savvy about the need to complete NCEA credits.
McKinley said last week's announcement of learning recognition credits was an "absolute bonus" that would help Auckland students especially see the light at the end of the tunnel.