The MetService is forecasting a "broad, complex low" will bring rain to most of the country this weekend.
The weather service says the North Island and upper South Island will be most affected by the system.
“The centre of the main low is expected to track southeast over central North Island during Sunday morning," MetService Meteorologist Rob Kerr says.
"However, the event will be well underway by then, with most of the rain in the warm northerlies east of the low centre, and sweeping over the North Island during Saturday, then on to the upper South Island early Sunday as winds there swing easterly."
There are no heavy rain warnings or watches in place yet, but MetService warns heavy falls may occur in northern and central areas.
"The areas of main concern are Northland to Bay of Plenty Saturday into Sunday, and Canterbury to Wairarapa Sunday into Monday,” Kerr says.
The Super Rugby Trans-Tasman final at Eden Park will likely be affected by rain at some stage, as well as the last day of Fieldays in Hamilton.