Updated 10:43pm — The second cold blast has arrived and this is the main Antarctic southerly, which is now sweeping over Southland, Otago and Canterbury.
Temperatures, which were already low, have dropped further.
The cold air has now reached Christchurch and is heading towards Wellington.
The polar blast will continue northwards – all of New Zealand will be colder this weekend.
Current wind map shows the southerly straight from Antarctica now moving into Otago and Southland.
Temp map as of 6pm.