A large complex low moves over New Zealand on Monday bringing unsettled weather to those in the north and west, in the evening cold southerlies develop about the far south.
Some morning sun possible for the upper North Island, the odd shower too. In the afternoon the risk of showers increases with the odd heavy fall and some thunder pushing in from the west, easing evening as northwesterlies change west to southwest. Morning rain eases to showers about the lower western North Island, there may be a heavy fall from afternoon about northern Taranaki then easing in the evening. Morning rain clears the east coast (Gisborne to Wairarapa) then expect some sun, further spits of rain later in the evening / overnight.
Morning rain eases to showers for the West Coast of the South Island, morning rain about Nelson / Marlborough clears then afternoon sun breaks through. Morning high cloud for Canterbury with any early spots of rain clearing, becoming mostly sunny in the afternoon. Mostly cloudy about Southland and Otago, the odd shower from afternoon then rain develops in the evening as south to southwesterly winds strengthen.
Map below showing temperature highs around New Zealand for various town / city centres. You will note that some eastern regions get back to warmer than average temperatures for the time of year.