High winds are causing problems across Mid Canterbury, with a woman taken to hospital after a tree fell on her car.
A strong, moist northwest flow is spreading north over New Zealand today, and is expected to last until late tomorrow.
The spring weather has brought thunderstorms to the West Coast of the South Island, with the eastern side of the country expecting strong wind gusts and warm temperatures.
A strong wind warning is in force for Canterbury, the Marlborough Sounds, Wellington and Wairarapa.
Fire Service spokesperson Andrew Norris said crews responded to reports of a car crushed beneath a tree at 7.30am today.
"Efforts by the crews were successful in releasing on occupant from the vehicle using rescue gear and the jaws of life, and that person was transported by ambulance with serious injuries."
He said crews had a busy morning dealing with trees over roads and power lines.
There is also a heavy rain watch for the Richmond Range and Rai Valley.
The West Coast was battered by a front overnight, with 10,000 lightning strikes in a two-hour period.
And the Wellington City Council said there has been a large slip on Manchester Street, behind the zoo, which has brought down trees and damaged cables.
Warmer temperatures were expected across the eastern side of the country, with highs of up to 22°C in Christchurch and Dunedin, while Napier was expected to reach 25° today.