Heavy rain is set to pummel parts of New Zealand days before blistering temperatures sweep the country. 

MetService forecaster Braydon White told the Herald there was potential for thunderstorm activity through the inland Gisborne, Hawke’s Bay area today. 

A severe thunderstorm warning has been issued for Bay of Plenty, Rotorua, Taupō, Gisborne and Hawke’s Bay. It will come into effect at 1pm and last for eight hours, with risks of flash flooding and slips. 

White said parts of the South Island were also in for a drenching. 

“There is a weak front sitting at the bottom of the South Island, which may bring showers to places like Invercargill and Dunedin.” 

White said a stronger front was forecast to arrive from the west on to the lower South Island tomorrow. 

“That will make its move north, affecting the West Coast and maybe Christchurch. 

“It will bring some heavier rain to the affected regions, especially to places like Greymouth, Hokitika and Milford Sound. 

“Alongside that, we get some reasonable westerlies. Nothing of warning level wind strength though. 

“But because it’s associated with the rain, we’re going to see those temperatures start to increase.” 

White said New Zealand was already experiencing “summertime temperatures”. 

“Tomorrow, it will be in the high 20s, and we’re looking into the 30s on Friday for a number of places.” 

The North Island is forecast to experience similar warm conditions today, tomorrow and Friday. 

“Places in the east start to get some of those northwesterlies coming down that can really crank up the temperatures,” White said. 

“Places like Gisborne, Napier, Hastings and even Whakatāne and Tauranga, we’re already starting to see those high 20s and low 30s. 

“But even places like Auckland and New Plymouth, we’re still seeing mid to high 20s.” 

White said this weekend was forecast to be even hotter. 

“Napier, Tauranga, Hastings, Whakatāne and possibly Blenheim and Kaikōura are going to see an extended period of heat. 

“Some places could be reaching the mid-30s.”