Monday kicks off with cooler southerlies but afternoon temperatures inland do lift today with some in the north breaking 20 degrees. 

High pressure between the South Island and Tasmania is growing and will grow to cover all of NZ by Wednesday and Thursday this week.

NORTH ISLAND:
Light winds inland with a possible early frost around places like Waiouru. Coastal areas mainly have a light S to SE breeze and while much of the North Island is dry today a few showers will brush coastal areas of the east, like around Hawke’s Bay/Mahia Peninsula and maybe Wairarapa – otherwise a dry day.
Highs: 15 to 21

SOUTH ISLAND:
A cool start then a fairly cool day too in the east and south with light winds, more southerly in coastal areas of the south and east but variable wind directions in the north and west. Warmest and sunniest weather today on the West Coast and around Nelson and Marlborough. 
Highs: 14 to 18

– WeatherWatch.co.nz