Saturday will be warmer than average across the entire country with fairly light winds. The light winds in the North Island will produce fog, especially in the upper North Island.
Warmer northerlies from the sub-tropics develop across the day with a warmer than average Saturday night on the way nationwide. On Sunday the day may start dry for many (perhaps not the West Coast) but rain and wind pick up as the day goes on with pockets of strong winds and heavy rain in the mix.
It all dries out again by Monday and Tuesday – but a brief cold southerly change arrives then too, before turning westerly for much of next week.