Kiwis across the country should be waking to mostly fine skies today before later bracing themselves for snow and a big freeze overnight.
"The coldest morning [so far] this year is set to occur Wednesday," forecaster Niwa says.
It means Auckland residents can expect isolated showers before a mostly fine afternoon and top of 15C. But overnight the mercury will plunge to 5C.
Those further north in Whangārei can expect a top of 15C and overnight low of 7C.
Hamilton residents should be waking to frosts and a sunny day with a top of 14C, but they will be reaching for the extra blankets tonight as the temperature plummets to 1C overnight.
Tauranga and New Plymouth are both expecting fine days with tops of 15C and 13C, respectively, and lows of 4C. Napier is heading for a high of 14C and overnight low of 3C.
Wellington is set for a top of 10C with a chance of afternoon showers, before dropping to a relatively balmy low compared to the rest of New Zealand of 6C overnight.
With snow falling down to 370m in parts of Otago yesterday, tonight's big cold should bring more falls across the South Island.
Christchurch is tipped to hit a top of 10C with isolated showers and a freezing -1C overnight.
Dunedin has a chance of showers in the morning before a fine afternoon and top of 10C. Overnight the temperature could fall to 2C.
Timaru residents should be waking to frosts this morning before a clear and sunny top of 11C. But overnight they are in for another freeze as the thermometer dips to -3C.
Queenstown is expecting a top of 8C today before also plummeting to minus 3C overnight tonight.
Today's weather
Whangārei: Morning cloud, then fine. Light winds. High 15C, Low 7C
Auckland: Morning cloud and isolated showers, then fine. Southerly breezes. High 15C, Low 5C
Hamilton: Fine, with early frosts. Southerlies. High 14C, Low 1C
Tauranga: Fine. Southerlies. High 15C, Low 4C
Rotorua: Fine, with early frosts. Southerlies. High 12C, Low 0C
New Plymouth:Fine. Southeasterlies. High 13C, Low 4C
Napier: Fine, then cloud increasing afternoon. High 14C, Low 3C
Whanganui: Fine spells. Southerlies. High 14C, Low 2C
Wellington: Cloudy periods, chance shower from afternoon. Southerlies. High 10C, Low 6C
Nelson: Fine with early frosts. Southwesterlies dying out. High 13C, Low 0C
Christchurch: Partly cloudy, with isolated showers and strong southwesterlies about Banks Peninsula. Clearing to fine in afternoon. High 10C, Low -1C
Dunedin: Cloudy spells with chance early shower, then becoming fine afternoon. Southwesterlies gradually easing. High 10C, Low 2C