A very cold southwesterly airflow lies over New Zealand today, especially the South Island where snow flurries are possible in the far south to near sea level. Overnight high pressure moves in and that means frost chances go up especially for much of the South Island and the Central North Island.

Northland, Auckland, Waikato & Bay Of Plenty
Morning rain then drying out in the afternoon with a few sunny spells breaking through. Northwesterlies change southwest early in the morning.
Highs: 17 – 19

Western North Island (including Central North Island)
Early rain eases to showers, clearing later on as strong westerlies ease changing lighter southeast at night. A few snow flurries get down to 700m for the Central Plateau before clearing. Frosty overnight for inland areas.
Highs: 11 – 15

Eastern North Island
Morning spits of rain clear, showers for Wairarapa in the afternoon as westerlies change southwest, showers may reach further north later in the evening, clearing overnight.
Highs: 15 – 21

Wellington
Morning sunny spells, chance of a spit, winds strong from the west. Southerlies in the afternoon bring cloud a few showers.
Highs: 13 – 14

Marlborough & Nelson
Spits or showers for Nelson, clearing in the afternoon. Marlborough is dry in the morning then showers develop afternoon, possibly heavy with a chance of small hail, clearing later on. Snow flurries to 600m. Strong westerlies change southwest around midday, dying out later. Frosty overnight.
Highs: 13 – 16

Canterbury
Showers, some heavy with small hail, snow flurries to 400m. Conditions start to ease for South Canterbury in the morning then further north in the afternoon with sun breaking through however showers may cling to inland parts of Mid Canterbury through into North Canterbury through to evening before clearing as cold southwesterlies die away. Frosty overnight.
Highs: 9 – 13

West Coast
Heavy showers with hail possible, clearing South Westland in the afternoon then further north in the evening. Snow to 300 possibly 200m for Fiordland, 400m further north. Strong cold southwesterlies die out at night. Frosty overnight inland.
Highs: 10 – 12

Southland & Otago
Wintry showers with hail and sleet, snow to low levels (perhaps even near sea level). Cold southwesterlies and showers ease evening. Central Otago has showers pushing into southern areas, further north may only see morning showers then sunny spells increase. Frosty overnight.
Highs: 8 – 10