If you live in and around Hamilton, make sure to get extra warm blankets out tonight. An overnight low of 3C is forecast, according to MetService.
A high of 16C is expected in the city today, however.
WeatherWatch analyst Aaron Wilkinson said those in the Waikato will see a mostly sunny day also. However, fog or mist was a possibility in the area this morning and later tonight.
Similar conditions are forecast in the Bay of Plenty, where light winds are also on the cards by this afternoon.
Western and central areas of the North Island, areas on the eastern part of the island and Wellington are all forecast to get a sunny day with some light winds.
The same conditions are expected in Marlborough and Nelson, Canterbury and the West Coast.
"[It's] mostly cloud about Southland, with the risk of a shower or two - long dry periods also," Wilkinson said.
That part of the country is, however, forecast to get westerly winds that will turn into stronger gusts this afternoon and those in Otago will see a lot more cloud by this evening.
Temperature highs of between 12C and 16C are forecast in those parts of the country.
Just before 7.30am, MetService said the coldest place was Masterton, which was recording a teeth-chattering 1.7C.
The warmest place at that time was Kaitaia, which was recording a temperature of 11.9C.
The wettest area was in Christchurch city, which had a 0.2mm rain accumulation level, while the windiest spot in New Zealand at that time was in Tauranga - clocking 15km/h strong winds.
Today's weather:
Whangārei 16C high, 7C low. Cloudy periods, one or two morning showers. Southeasterlies.
Auckland 17C, 8C. Becoming fine, but isolated afternoon showers possible.
Hamilton 16C, 3C. Partly cloudy, chance of shower until evening.
Tauranga 17C, 7C. Partly cloudy, chance of showers until evening. Light winds.
New Plymouth 15C, 5C. Fine. Light winds.
Napier 17C, 6C. Fine with morning frosts. Evening cloudy periods and light winds.
Whanganui 17C, 5C. Fine. Light winds.
Wellington 14C, 6C. Fine. Light winds.
Nelson 15C, 4C. Fine. Light winds.
Christchurch 16C, 4C. Fine with morning frosts. Evening cloud and light winds.
Dunedin 16C, 8C. Cloudy periods. Winds tending southwest.