MetService is warning of a return to rough weather next week - caused by a deep low forming in the Tasman Sea.
Photo: 123RF
Forecaster Andy Best said temperatures in the South Island will be six degrees below average.
In the North Island, it will be wet and muggy on Monday.
Mr Best said by midweek, there is likely to be heavy rain and high winds, making it dangerous on the roads.
The South Island's West Coast, which has been badly affected by heavy rain this month, can expect more rain from tomorrow and it may be heavy by Monday.
By Tuesday the rain would move north to Nelson and Marlborough.
In its latest post to Facebook today, MetService is warning of thunderstorms in North Otago and Canterbury tomorrow.
The thunderstorms may spread to Northland, Auckland and Great Barrier Island later in the day.
The bad weather is set to affect the country for four days through to Wednesday.