Auckland has moved to alert level 3 for seven days and the rest of the country to level 2.
The Selwyn Sounds music festival planned for March 6, featuring Stan Walker and Hello Sailor, has been rescheduled to April 10.
The Christchurch Armageddon Expo planned for this weekend has also been rescheduled to May 29-30.
Otago's annual Motatapu race has been cancelled in the wake of the change of alert levels.
The Crusaders rugby game against the Hurricanes on Saturday at Christchurch's Orangetheory Stadium will go ahead without a crowd.
The Silver Ferns' four-month Constellation Cup series with Australia, starting on March 2 in Christchurch, will be affected.
Netball New Zealand has yet to announce its plans but the games in Christchurch and Tauranga next week will have to continue without fans.
The Golden Shears, the international shearing and woolhandling championship, has been cancelled for the first time in 61 years.
The upcoming Grand Final of New Zealand's National Concerto Competition has been postponed, with a new date yet to be set.
But the show goes on at the court theatre, where plastic screens have been put between audience rows to enforce physical distancing.
Events that have been cancelled include:
- Christchurch Holi-Festival of Colours, scheduled for 6 March
- Childrenās Day in the Residential Red Zone, scheduled for 7 March
- Lazy Sundays, scheduled for 7 March
Events that have been postponed include:
- Armageddon Christchurch, scheduled for 6 and 7 March
- 2021 Bunnings National Touch Championships at NgÄ Puna Wai, scheduled for 4 to 7 March.
- SVA Big Give 2021, scheduled for 6 March
- Memorial Cup, scheduled for 6 March
- Secondary Schools Waka Ama Champs, scheduled for 6 March
Said Christchurch City Council events and arts manager Tanya Cokojic: āThe COVID-19 alert level change means that event organisers are having to re-think their plans and unfortunately postpone or cancel events that are likely to draw more than 100 people.
"If you had plans to go to an event in the coming days, I recommend that you check in with the organisers to see whether it is still going ahead."
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