A cold front pushes northwards of the South Island today reaching the lower North Island this afternoon. Frosty conditions can be expected about the lower South Island overnight as cloud and showers clear.

Northland, Auckland, Waikato & Bay Of Plenty
Morning cloud then mostly sunny, some cloud again later in the evening / overnight. Southwesterly winds.
Highs: 18-19

Western North Island (including Central North Island)
A dry morning with partly cloudy skies, northwesterly winds. Showers develop mid to late afternoon as winds change southeasterly, clearing overnight for most however continuing about the Central Plateau where some snow lowers to 800m overnight.
Highs: 14-16

Eastern North Island
Sunny weather, showers push into Wairarapa in the afternoon with a southerly change, moving further north in the evening. Some rain about Hawkes Bay and Gisborne for a time later in the evening / overnight. Snow flurries lower to 600m about the ranges of Wairarapa for a time overnight, accumulations fairly minimal.
Highs: 17-21

Wellington
A mostly sunny morning then afternoon showers with a southerly change.
High: 15

Marlborough & Nelson
A dry morning with some high cloud, afternoon showers develop as southeasterlies freshen. Snow lowers overnight for a time to 500m before clearing.
Highs: 15-16

Canterbury
Occasional showers develop early morning with cold southwesterlies. Banks Peninsula and Christchurch near the coast may see showers becoming a little more infrequent from afternoon. Expect small hail at times, snow flurries lowering to 400m in the afternoon.  
Highs: 10-13

West Coast
Early showers clear South Westland then becoming mostly sunny, rain further north clears during the morning then sun increases from afternoon. Mid to late afternoon cloud and a few isolated showers are possible about the ranges of South Westland, chance heavy with some hail / then clearing in the evening. Southwesterly winds.
Highs: 14-16

Southland & Otago
Showers with a risk of small hail, easing from afternoon and clearing later in the day, overnight for coastal Otago. Sun may break through at times. Snow flurries to 400m. Cold southwesterly winds. Frosty overnight as cloud breaks and winds drop out especially about inland areas.
Highs: 8-11

By Weather Analyst Aaron Wilkinson – WeatherWatch.co.nz