"Tomorrow unfortunately things do start to deteriorate for the North Island. Pretty much everywhere we're expecting rain," Little said.
"Places that are sheltered from northerly flows, like Gisborne, Hawke's Bay, the Wairapa, Whanganui and Manawatu. They will have less rain than places further north and west, but we're still expecting very cloudy conditions and there'll still be some rain for those areas so it's really an indoor day.
"People who have plans for the weekend, today for the North Island is definitely looking like the best day to get out and about and enjoy the outdoors."
Another weather phenomenon people in the North Island are currently experiencing is especially radiant and colourful sunsets created by smoke from the New South Wales bush fires.
"Unfortunately in NSW these wildfires burning and yesterday we could see large plumes of smoke from satellite imagery pushing into the Tasman," Little said.
"There's northwesterly winds aloft and they've been an ideal direction to bring that smoke across to New Zealand.
"Unfortunately it's going to be quite cloudy in many places but areas that do have clear skies for tonight's sunset may notice it a bit more colourful than normal. The sun can refract off more particles."
Elsewhere around the country the conditions are going to be quite stormy with a raft of severe weather warnings and watches in force.
"Unfortunately it's looking pretty rough in many parts of the country. "A lot more rain to come in the already saturated parts of the South Island. We're also expecting strong winds in many parts of the country as well over the next couple of days.
"Wind watches are in force basically from the Bay of Plenty, Gisborne, South Taranaki, Whanganui, Taihape, parts of Hawke's Bay.
"We have a heavy rain watch for many parts of the North Island, more from Sunday into Monday, and that includes Auckland, Waikato, Taupo.
"So once the front moves northward we are expecting the weather will deteriorate. But that's not really until tomorrow."
Along with the storms will be high humidity and temperatures across the entire east coast of the country.
"We've got this persistent northerly flow and that's brought very warm air down from up towards the tropics and partly that's why we've had this very good potential for heavy rain for the South Island and for other areas as the front moves north," Little said.
"It's being fed by a lot of this moist warm air and that's also led to the very humid conditions and also for eastern areas some very high temperatures in the afternoon."
Nearly all major cities across the country are over 20C today, with Napier reaching 28C and Christchurch hitting 27C.
Forecast this Saturday across New Zealand:
Whangarei: High of 23C. Cloudy periods and a few showers, increasing at night. Northeasterlies.
Auckland: High of 22C. Fine spells and isolated showers, but cloud increasing again this evening. Northeasterlies, picking up afternoon.
Hamilton: High of 24C. Chance shower. Fine spells, but cloudy again this evening. Northerlies.
Tauranga: High of 21C. Fine spells, but cloudy with possible drizzle this evening. Northerlies.
Rotorua: High of 20C. Fine spells, but cloudy with possible drizzle this evening. Northerlies.
New Plymouth: High of 20C. Occasional rain, clearing evening. Northerlies.
Napier: High of 28C. Fine and warm. Northwesterlies.
Palmerston North: High of 25C. Partly cloudy, chance afternoon shower. Northerlies.
Wellington: High of 18C. Mostly cloudy. Occasional rain clearing evening. Northerlies, strong in exposed places.
Blenheim: High of 22C. Cloudy periods. A few showers. Northwesterlies.
Nelson: High of 19C. Mostly cloudy, rain at times, more persistent from afternoon. Northerlies.
Greymouth: High of 17C. Periods of rain, chance heavy. Thunderstorms possible. Northeasterlies.
Christchurch: High of 27C. A warm day, with thick high cloud. Northerlies.
Queenstown: High of 20C. Rain at times. Westerlies.
Dunedin: High of 24C. A warm day with high cloud. Northeasterlies.
Invercargill: High of 20C. Periods of rain, possibly thundery. Northerlies turn lighter westerly this afternoon.