Antarctic blast: How the big chill will affect you

The wintry blast expected to hit on Tuesday won't be felt equally across the country.

What passes for cold in Auckland doesn't in Dunedin, and vice versa.

Here's how the first big chill of the coming winter will affect your region.

Southland

The sun won't do much to warm up the south, with an overnight low of 3degC barely rising to 5degC by midday. Then the rain kicks in and it starts to get colder again thanks to some cold southwesterlies, according to the MetService.

Otago

It's not much better for their immediate neighbours to the north, who'll shiver in 2degC temperatures overnight, and bask in 7degC heat Tuesday afternoon. Morning show showers will turn to sleet, the MetService says.

Canterbury

Oddly enough, it'll be hotter at midnight Tuesday morning - 8degC - than it will be at midday, with temperatures peaking at 6degC. The morning will be rainy too, with snow down to about 400m.  It'll be slightly warmer in Christchurch - but still only 8degC.

"Most of the South Island [will be] over 8degC below normal for this time of the year," said WeatherWatch's Philip Duncan.

Nelson

Temperatures all downhill from Monday's high of 20degC. A mild morning will give way to cold and wet afternoon, dropping down to 8degC. Gale-force winds are possible too.

Marlborough

It's a similar story in Marlborough, with temperatures peaking in the morning at 10degC, dropping to 5degC by the evening. Heavy rain and sleety showers are possible, as are gales - particularly around the Sounds.

Wellington

Raining and windy, with temperatures plummeting from 14degC overnight to a bone-shaking 7degC.

"Severe thunderstorms are likely across the North Island as cold and warm air mix," said Philip Duncan. "There will be several peaks of heavy rainfall starting from Monday evening over Canterbury and areas around the Cook Strait."

Wairarapa

After a dry, warm morning, rain comes in and the temperature will drop from 15degC to 10degC by midday, falling further again to 5degC late in the evening. It'll be raining.

Manawatu

Raining, and getting colder as the day goes on. It'll be about 15degC when you wake up, but 8degC when you go to bed - so consider getting an extra blanket ready.

Hawke's Bay

Bucking the trend, temperatures in Hawke's Bay will peak around midday at 20degC before falling to a relatively mild 9degC overnight. There will be spots of rain, but the wind's coming from the north and west, so it won't get so cold.

Taranaki

Taranaki residents will be glad to hear they're largely unscathed too, at least until late Tuesday night. It'll be 18degC most of the day, before falling to 7degC after the sun sets. Might be some thunderstorms and 120km/h wind gusts though.

Bay of Plenty

High of 19degC and a fine afternoon - but with a downpour expected around midday. Southwesterly winds late in the evening will drop the mercury to 8degC.

Coromandel

Much like the neighbouring Bay of Plenty, it'll be relatively warm - 20degC - but with rain around midday, probably a bit more than in the Bay. Gale westerlies are expected, with winds up to 120km/h.

Waikato

High of 19degC, but even more rain the Bay and Coromandel according to the MetService. Like those regions, it'll be clustered mainly around midday. Gales are possible. Tuesday night will be a lot colder than Monday night.

Auckland

As above - high of 19degC, rain around midday. "Squally" thunderstorms are possible, according to the MetService. Winds, like elsewhere, could get up to 120km/h. While Monday night's temperatures will only go down to 16degC, it'll plummet to 8degC Tuesday night/Wednesday morning, so be prepared.

Northland

Residents up north could be forgiven for not knowing there was a wintry blast at all. A balmy 20degC temperature in the morning gives way to 14degC overnight, twice as hot as most other regions. It'll be raining though, with severe gales possible in the evening.

Newshub.