Severe gale warnings have been lifted for most of the country but the rain is set to continue for most.
Competitors in the Triathlon World Series grand final in Auckland struggled in the rain that fell across Auckland and much of the North Island today.
The weather was particularly bad across Waikato, with thunderstorms expected to continue.
Auckland rugby player Alby Mathewson tweeted today that his plane was struck by lightning. Auckland played Wellington in the capital last night in the ITM semifinal.
MetService analyst Ian Gall predicted rain easing to showers overnight for the North Island and overnight snowfall in the South Island.
Mr Gall warned travellers that some alpine roads - Lindis to Lewis Pass, Porters Pass and Arthurs Pass, may be closed tomorrow morning.
He said temperatures would drop across the South Island tonight.
Christchurch's temperature was expected to drop from a maximum of 20 degrees today to 10 degrees tomorrow.
Temperatures across the North Island would remain stable between 16 and 18 degrees, and cooler temperatures were forecast overnight.
"The rest of the weekend is not looking good for anybody," Mr Gall said.
Mr Duncan said the weather would improve on Tuesday with snow and showers starting to ease.
- APNZBy Siobhan Leathley