A low just west of New Zealand is bringing cool southerlies and rain that will gradually move over the country today.
Heavy rain warnings are still in force for Westland, with the ranges south of Otira expected to get a further 70 to 100mm of rain on top of what fell yesterday. The heaviest falls were expected early this morning.
There is also a low risk of thunderstorms to northern Westland, Buller and parts of Nelson and northern Marlborough.
A heavy rain watch also covers the possibility of rainfall accumulations reaching warning criteria in the Tararua Ranges today. The warning is in place from 9am to 9pm tonight.
For the upper North Island expect mostly cloudy skies, a few showers from late afternoon or evening.
About the lower western North Island, expect the odd shower then some rain from afternoon, winds generally from the west or northwest.
There will be sunny areas and some high cloud for the east coast, with winds from the northwest. Some rain is expected to move into Wairarapa during the afternoon, with southerlies.
It will be cloudy about Nelson and Marlborough, dry at first then rain develops during the morning. Canterbury will see morning rain then showers, and cool south to southeasterly winds.
It will also be mostly cloudy along the West Coast and about Otago with areas of rain or showers, however Southland will be mainly dry after any morning rain clears.
The rest of the week is not looking much better, with heavy rain expected to persist in Westland north of Otira, Buller and the ranges of northwest Nelson during Thursday.
For the remainder of Nelson, Marlborough, Canterbury north of Rangiora, and from Wellington to Horowhenua, including the Tararua Range, there is also the chance of warnable amounts of rain tomorrow.
Additionally, there is low risk of warning amounts of rain in Wairarapa, Hawke's Bay, Manawatu to Waitomo, and across to the eastern ranges of Bay of Plenty.
A new low pressure system will then approach New Zealand from the Tasman Sea on Friday, bringing a period of heavy rain to some regions during the weekend.
Cloudy periods, chance of a shower from afternoon. Westerlies. High 26C / Low 16C.
Auckland: Cloudy periods. One or two showers in the west, spreading elsewhere in the afternoon. Rain developing overnight. Northwesterlies. High 23C / Low 16C.
Tauranga: Fine, then cloud increasing in the evening with the chance of a shower. Westerlies. High 25C / Low 17C.
Hamilton: Cloudy periods and chance shower. Rain developing evening. Westerlies. High 23C / Low 15C.
New Plymouth: Showers, turning to rain in the afternoon with heavy falls and thunderstorms possible. Northwesterlies. High 21C / Low 14C.
Napier: Cloud increasing with occasional rain developing afternoon. Northerly breezes. High 27C / Low 17C.
Wellington: Rain, briefly heavy as northwesterlies change southerly around midday. High 21C / Low 13C.
Nelson: Periods of rain, possibly heavy and thundery afternoon. Northerlies dying out morning, easterlies at night. High 22C / Low 13C.
Christchurch: Rain. Southerlies. High 17C / Low 9C.
Dunedin: Rain, easing in the afternoon. Southeasterlies, tending northeast in the afternoon. High 13C / Low 10C.