A cold front pushes northwards over the South Island today, strong northwesterlies ahead of the front then changing westerly in behind. The flow changes southwest overnight.

Northland, Auckland, Waikato & Bay Of Plenty
A mix of sun and cloud, the odd shower, more so in the morning then again later in the day. Northwesterlies.
Highs: 15 – 16

Western North Island (including Central North Island)
Cloudy areas and a few showers, drying up in the afternoon a little with sunny spells breaking through. Rain overnight, thunderstorms possible for Taranaki. Breezy northwesterlies.
Highs: 11 – 16

Eastern North Island
Sunny with light northwesterlies, picking up in the evening. Rain overnight for Wairarapa.
Highs: 16 – 20

Wellington
Partly cloudy, a spit or two possible mainly in the north. Rain later in the evening or overnight. Strong northwesterlies rising to gale from afternoon.
High: 14

Marlborough & Nelson
Mostly sunny with breezy northwesterlies, rain develops in the evening spreading from the west as a cold front passes over.
Highs: 15 – 17

Canterbury
Mostly sunny, during the afternoon rain spreads northwards (more persistent inland, spits near the coast) as a cold front pushes over, clearing up in the evening. Northwesterlies strong for a time in the afternoon. Rain again overnight north of about Banks Peninsula.
Highs: 10 – 17

West Coast Early rain eases to showers, heavy rain pushes northwards during the afternoon thanks to a cold front bringing a chance of thunderstorms and hail as northerlies change westerly. Conditions ease back for a moment in the evening then heavy showers and thunderstorms develop again overnight with winds changing strong southwest. Snow to 300m in the south later in the day, 600m further north overnight.
Highs: 12 – 14

Southland & Otago
Early morning spits clear, rain in the afternoon (heavy in the west), clearing evening. Rain again overnight as strong northwesterlies change southwest (gales for coastal areas), thunderstorms and hail possible for Southland. Snow to 300m overnight.
Highs: 10 – 14