The previous daily admission record was 138 people.
New Year's Day and the day after, both public holidays, backed on to a weekend this year, which was a likely factor in the increase, Dr Roberts said.
"That's probably why it's so much higher than last year."
On both public holidays GP offices were not open, though after-hours provider White Cross Healthcare was.
"I think you know it's always a busy time," Dr Roberts said. "It's not a complete surprise."
While most of the people on January 2 did need to be in the ED, there was likely a small number who could have gone to an after-hours doctor, he said.
"Even 10 [fewer] makes a difference," he said.
"That is desperately hard work for everybody down in the emergency department." Dr Roberts knew of staff who had stayed late and skipped their lunch breaks so patients waited less time to be seen.
He said staff had coped "extremely well".
While it was too early to pin down which were the most common injuries or illnesses that presented over the holiday period, alcohol was a likely factor.
The increased number of tourists in Northland at this time of year had probably contributed to the increase too. "There would be a lot of them who would have come from out of town," Dr Roberts said. "There are a lot of minor injuries when people come out on holiday."
A spokesman for White Cross said January 2 was the busiest day the after-hours service had seen in the past eight years.
The 131 patients who were seen meant two on-call GPs and a number of extra nurses had to be called in. "It has certainly been busier than usual," he said.
It appeared there were increased numbers of people with illnesses, which could have been the flow-on effect of a busy influenza season that peaked in September, the spokesman said.
It was also likely many people who went to the ED from out of town did so because they did not know White Cross was open, he said.
