Kiwis in the top of the country are waking up to a muggy morning as two weather systems collide over New Zealand, bringing rain and possible thunderstorms for much of the country. 

Auckland, Whangārei and Kaitāia were all sitting at 21C just before 7am today with 95% humidity or higher. 

Tāmaki Makaurau will reach a high of 27C today. 

MetService forecaster David Miller told the Herald a subtropical airmass was moving down over the North Island, while fronts were moving up the South Island. 

“They [will] combine into one.” 

Miller said much of the country would have showers today. 

MetService has issued multiple heavy rain watches for the west of the South Island, Coromandel and the Bay of Plenty. 

A heavy rain watch is in force for the Coromandel Peninsula until 9am today, while another heavy rain watch in place for the Bay of Plenty, west of Kawerau, will expire at noon. 

In the South Island, heavy rain watches are in force along the entire western side of the island. 

The heavy rain watch for Fiordland, west of the Lakes, is forecast to expire early this morning. 

The Buller District, the Grey District and Westland District ranges are under a heavy rain watch until late this afternoon. 

Meanwhile, a heavy rain watch is forecast to come into force for the Tasman District and about west of Motueka at 6am and last for 15 hours. 

MetService has also warned of possible thunderstorms across most of the North Island and parts of the South Island this afternoon and this evening. 

“There could be very heavy rain in spots outside the broad-scale watch areas.” 

Miller said the worst of the rain would clear off the country tomorrow. 

“The country will be a broadly southwesterly flow and any remaining showers should clear, by and large. 

“We can still expect to see a few showers in the west of the South Island and a few lingering showers in the northeast of the North Island. 

“It’s a pretty similar story on Sunday.”