Temperatures in the North Island will reach into the low 20s today but central parts of the country will face wind and bands of rain through the day.
It comes ahead of heavy rain and gale-strength winds predicted for the weekend.
A complex low-pressure system covering the North Island and Tasman Sea was directing moist easterly flow and rain across central New Zealand today, MetService said.
The flow was expected to tend southerly through the day and ease the rain over central areas.
A heavy rain watch was in place for Gisborne north of the city and Canterbury north of the Waimakariri River.
There was also a low risk of thunderstorms about Gisborne this morning.
Looking ahead, a ridge of high pressure would cover much of the country on Thursday.
This would be followed by a complex low-pressure system that was expected to move on to New Zealand from the Tasman Sea over Friday and Saturday.
The complex low would bring rain and strong northeast winds in many places.
"There is low confidence of northeasterly winds approaching severe gale strength in exposed places of Northland, Auckland, Coromandel Peninsula and Waikato from late Friday to Saturday."
There was also low confidence rain accumulations would reach warning amounts in Northland and Auckland, and the western ranges of Nelson on Saturday.
"There is moderate confidence that rainfall accumulations will reach warning amounts in Coromandel Peninsula, Bay of Plenty and about East Cape during Saturday and Sunday."
Yesterday MetService said there were around 800 lightning strikes in New Zealand, with most of them occurring in Hawke's Bay, Gisborne and Northland.
: Fine, morning high cloud. Southwesterlies. High 23C Low 14C
Auckland: Mainly fine, morning high cloud then becoming cloudy tonight. Southwesterlies. High 22C Low 14C
Tauranga: Cloudy at times. Afternoon and evening showers, could be heavy and thundery. Southwesterlies. High 24C Low 15C
Whanganui: Cloudy at times. Possible afternoon shower. Southerlies. High 22C Low 12C
Napier: Cloudy with occasional showers. Southeasterlies turning southwest. High 20C Low 14C
Wellington: Mostly cloudy. Showers, mainly about the south coast and eastern hills. Southerlies, strong at times. High 18C Low 12C
Christchurch: Rain easing from midday, but remaining cloudy. Southwest turning easterly. High 16C Low 11C
Dunedin: Cloudy, with drizzle morning and night. Northeasterlies. High 15C Low 12C