Thunderstorms, heavy showers and hail are on the cards for the North Island in another wicked day of weather.
It comes after Auckland was pelted with heavy rain, hail and lightning yesterday, and even water funnels in the Hauraki Gulf.
MetService meteorologist Karl Loots said another active system was forecast to move over the North Island this morning, bringing a moderate risk of thunderstorms with heavy showers and even hail.
Yesterday, eastern parts of the South Island were hammered with heavy rain, while snow fell at high altitudes.
To 3pm yesterday 83.5mm had fallen in Methven, 69.8mm in Roxburgh, 67.0mm in Waitati and 65.6mm in Ashburton. There were reports of flooding in parts of Otago forcing some residents to evacuate their homes.
Nearly 50mm fell in the Dunedin area over a 12-hour period, causing surface flooding, slips and the Taieri River's spillway to be opened.
Dozens of roads were closed, and residents in Henley south of Dunedin were evacuated as river levels rose.
Loots said the rain stopped down south about 9pm last night, and should remain fine for the morning before some moderate showers around midday.
Middlemarch residents were being advised not to drink water from private bores as it was likely to be contaminated after extensive flooding.
Dunedin Mayor Dave Cull said it was distressing when people had to be evacuated.
It was the fourth year in a row they'd had flooding, but this time things could have been worse, he said.
State Highway 1 south of Milton was closed to cars, due to flooding but open to 4WDs and trucks.
The North Island would start the day relatively fine, but in the Tasman Sea were heavy showers, hail and thunderstorms that were due to move over western areas from Northland to Taranaki early morning.
The thunderstorm risk would spread across much of the North Island by the afternoon and early evening.
The heavy showers and hail would move over inland parts of Buller, Nelson and Marlborough later today.
The severe weather would start to ease tomorrow, with just some isolated across the North Island, Loots said.
Then late Thursday and Friday another front would come through from the Tasman Sea bringing rain to Northland and Auckland, before spreading over the whole country overnight Friday into Saturday.
"It is going to be a rainy period, and unfortunately it will not be clearing for the weekend. We will be stuck in a flow of low after low, and slow moving too."
As the system was coming down from the tropics Northland and Auckland would begin to feel very humid from Friday onwards.
Showers developing in the morning, chance heavy and thundery with hail, easing evening. Northwesterlies. 17C high, 11C overnight.
Showers developing in the morning, chance heavy and thundery with hail, easing evening. Northwesterlies. 16C high, 11C overnight.
Showers from late morning, chance heavy and thundery with hail, easing evening. Northerlies. 15C high, 7C overnight.
Tauranga Fine start, but showers from late morning, possibly heavy and thundery. Northerlies. 16C high, 9C overnight.
New Plymouth Showers from late morning, chance heavy and thundery with hail, easing evening. Northerlies. 15C high, 7C overnight.
Napier Mainly fine. But cloud increasing and a few showers from afternoon. Northwesterlies. 19C high, 8C overnight.
Whanganui Fine morning. Cloudy periods and one or two showers in the afternoon and evening, possibly heavy. Light winds. 18C high, 8C overnight.
Wellington Mostly cloudy with a few showers, chance heavy. Southeasterlies developing. 16C high, 9C overnight.
Nelson Fine spells until afternoon, then a few showers. Light winds. 16C high, 7C overnight.
Christchurch Fine spells and chance of a shower, especially from afternoon when some could be heavy. Northeast breezes. 16C high, 6C overnight.
Dunedin Fine until midday, then clouding up and rain developing. Southerly breezes. 14C high, 10C overnight.
It's understood a NZDF aircraft and multiple helicopters are involved.