Waka Kotahi NZ Transport Agency is reporting strong wind warnings are in place for SH1 Dunedin-Ashburton and Dunedin-Glenavy as well as SH85 Alexandra-Palmerston.
NIWA is advising people to dress in layers as chilly air will make it feel colder than it really is.
In Auckland, temperatures should remain relatively high today but rain is forecast for the late morning and afternoon.
An orange heavy rain warning was in force for Westland until 11am.
Heavy rain watches remain in place for Buller, the Tasman ranges and the Tararua Range until this evening.
Strong wind watches are in place for coastal Southland, Dunedin and Clutha.
It follows a warmer night for many, with temperatures barely dropping below 20C in a number of places.
The severe weather is expected to continue until at least Friday, with morning frosts possible in some places.
Temperatures are expected to drop a few degrees across the North Island from Thursday.