Much of the country shivered in frosty early morning weather, with icy conditons halting train services on the Kāpiti line into Wellington.
Multiple trains were waiting to leave Waikanae for Wellington early today but could not get through because of the conditions.
Trains were running to timetable again later in the morning, Metlink said.
Temperatures had dropped in the region overnight with Paraparaumu recording -1C at 7am.
Most of the country was at or near freezing and MetService urged drivers to watch out for ice.
St Arnaud was the the coldest spot on -7.8C.
Brrrrrr who's feeling the cold this morning?!?
— MetService (@MetService) July 13, 2021
St Arnaud takes the coldest spot again this morning with -7.8°C!
With most of the country near or below freezing, be careful and watch out for ice!
Check out your forecast for today at https://t.co/Yjbq0jxdqz
^AR pic.twitter.com/ucsReUX3TM
Christchurch, where temperatures plunged to -4C this morning, drivers are being urged to take care.
Christchurch City Council said there was ice on roads that would not normally be affected.