Areas currently at the red traffic light setting are due to move to orange at midnight tonight, apart from Northland.

The country left behind the alert level system that had been in place since early in 2020 and moved into the traffic light system - formally the Covid-19 Protection Framework - on December 3.

Today marks the first signalled shift of the new framework since then.

The system involves three settings - green, orange, and red.

Here is more information about what you can and cannot do under the settings:

• Explained: What the traffic light system is and how it works

At 11.59pm tonight, the following areas move from red to orange: Auckland, Taupō, Rotorua Lakes, Kawerau, Whakatāne, Ōpōtiki, Gisborne, Wairoa, Rangitīkei, Whanganui and Ruapehu districts.

Northland will remain at red.

At orange, gathering limits can lift if vaccination certificates are used.

Hospitality, gatherings, events, close contact businesses, and gyms will not have to limit the number of people on the premise or apply physical distancing.

Without the use of certificates, gatherings such as social sport, places of worship, weddings and funerals can have up to 50 people based on 1-metre physical distancing, but gyms and close contact businesses, such as hairdressers, are not able to operate. Hospitality outlets must be contactless only.

Epidemiologist professor Michael Baker urges people to stay vigilant while having more freedom and to get a test if they have symptoms.

"Some people will be infected without having symptoms so it is important everyone is alert to getting tested if they have any symptoms. Obviously we are in summer time now, there are fewer respiratory viruses in circulation."

Whangārei Mayor Sheryl Mai says Northlanders have got used to the red traffic light settings, so it will not be too hard.

Cases are still emerging in her area and people need to get vaccinated and get tested if they are feeling unwell, Mai says.

"Cases are not spiking at this point so hopefully with the evidence and all of the assessment they can review our scenario and hopefully move Northland to the settings of the rest of the country in a couple of weeks."

Vaccination rates for Northland sit at 88 per cent for first dose and 84 for second doses.

-RNZ.