The coolest temperatures are expected in Otago and Southland where 6-8C is forecast throughout the day and a freezing -4C is predicted in Invercargill overnight.
Yesterday the warmest temperature in New Zealand was in Kaitaia at only 14.4C, which is the coldest maximum temperature at Kaitaia since September 11 last year.
Metservice meteorologist Ravi Kandula said most of the South Island is set for fine weather and a bit of cloud around the ranges, Banks Peninsula and Otago.
"In the North Island, south of about Taupō, showers are continuing in a southerly flow with more about the coast as you would expect. These will drift as far north as Gisborne and Mahia Peninsula but further north is fine.
"Going into tomorrow, the ridge continues to build and the southerly flow continues over the North Island bringing isolated showers. Within the South Island it is expected to be fine and that trend will hold into Thursday.
"A slight northeast flow will then begin to build over the upper North Island, bringing some showers to parts of Northland and Auckland," Kandula said.
"But essentially over the next few days we are talking an easing southerly flow, with a ridge building over the country and frosty conditions for many parts of the country. There will be fog for sheltered places as well."
Today's forecast
Whangārei: Fine. Fresh southerlies easing in the morning. High 14C / Low 5C.
Auckland: Fine. Southerly breezes. High 13C / Low 5C.
Tauranga: Fine. Southerly breezes. High 15C / Low 4C.
Hamilton: Fine with early frosts. Southerly breezes. High 14C / Low 0C.
New Plymouth: Mostly fine but chance shower. Southeasterlies, strong for a time in the morning. High 12C / Low 4C.
Napier: Mostly cloudy. A few showers clearing evening. Southerlies.. High 12C / Low 6C.
Palmerston North: Fine. Light winds. High 11C / Low 4C.
Wellington: Mostly cloudy, with showers easing from afternoon. Strong southerlies easing afternoon. High 10C / Low 7C.
Nelson: A crisp, clear day with early frosts and light winds. High 12C / Low 0C.
Christchurch: Fine spells, with a few showers mainly about Banks Peninsula. Southwesterlies dying out evening. High 9C / Low 1C.
Greymouth: Fine with early frosts. Light winds. High 11C / Low 1C.
Dunedin: Partly cloudy. Southwest dying out in the morning. High 8C / Low 3C.
Queenstown: Mainly fine with early frosts, low cloud possible in the morning. Light winds. High 6C / Low -3C.
Invercargill: Partly cloudy, with morning frosts. Light winds. High 8C / Low -4C.