Weather: Thunderstorms, flooding, funnel clouds, heavy rain and hail hit New Zealand

A state of emergency has been declared in Napier following heavy flooding on Monday.

"Shelter at home and avoid driving where possible," the Hawke's Bay Civil Defence Facebook page warns.

"If you feel unsafe at home, self-evacuate to family and friends first. If you need urgent help because you are in danger, call 111."

Around 100 properties have affected by the flooding and dozens of people evacuated as the heavy rain hammers down.

An elderly woman trapped in her home was one of those rescued by emergency services. The 75-year-old was on Bluff hill where heavy downpours have popped manholes and completely closed streets.

Power is out in parts of Napier and the city's wastewater network is overrun. Residents are being asked to hold off flushing toilets and using showers for now.

"We are triaging calls for assistance for homes flooding and roofs leaking, and have removed some elderly from their homes to stay with relatives," says Fire and Emergency NZ Area Manager Ken Cooper.

"Hawkes Bay's Urban Search and Rescue team is assessing a number of landslips on Napier hill caused by the heavy rain.

"People should stay home and dry, and travel only if it is essential. If they need assistance please call 111."

As heavy rain and hail hits the North Island, tornado-like funnel clouds have emerged, leaving residents terrified.

The cone-shaped clouds were seen fizzing above Whakatane at around 4:30pm on Monday.

Whakatane News captured a photo of a cone-shaped cloud forming in the Bay of Plenty region.

"Couple of little sprouts currently forming above us," it said in a Facebook post.

Funnel clouds are not dangerous unless they reach the ground, according to WeatherWatch.

"A funnel cloud isn't a tornado - but a tornado is formed when the funnel cloud connects with the ground.

"Not all funnel clouds become tornados," it added.

Hail in Sunnynook, Auckland.
Hail in Sunnynook, Auckland. Photo credit: Supplied / Benjamin McCardle

A resident in Auckland's Sunnynook shared a photo of strong hail rolling through their back yard.

MetService meteorologist Rob Kerr says we will be seeing heavy rain or showers from now to later on Wednesday.

"Severe weather warnings and watches are in place across eastern parts of the North Island for Monday and Tuesday, with the main area of concern being the ranges of Hawke's Bay and southern Gisborne."