He said the heat was being brought in by a ridge bringing tropical air from across the Tasman on a north-westerly.
"The air around that is coming from the North Tasman Sea that will see the temperatures pumping up in Northland over the next few days," he said.
Monday to Wednesday next week should bring plenty of sun and daily highs of 25C or 26C before rain comes on Thursday and the temperature drops to a predicted high of 23C on Friday and 21C next Saturday.
The heat comes after it was announced this week that Northland was the hottest region in the country last year, for the fifth year running.
All of Northland's six weather stations featured in the top 15 hot spots, with Whangarei leading with a mean average temperature of 16.9C, recorded at Whangarei Airport.
This was Whangarei's second highest reading since 1967 and while the weather data is collected at the airport and the thermometer would have reached up to 4C higher inland.
Whangarei Mayor Sheryl Mai has reacted to news that Whangarei is the hottest place to be saying it's only part of the picture for the district.
"When you're hot, you're hot, and Whangarei is the hottest of the lot. Our climate makes us the subtropical capital of New Zealand, affording us year-round enjoyment of our environment," Ms Mai said.
"But that's only part of the picture; we're hot in every other way, too. We've got spectacular beaches, lush forests, wonderful craft and produce markets and friendly people. Right now, the action-packed, three-month Endless Summer Festival is also in full swing, with its signature Northland Pasifika Fusion and Fritter Festivals still to come.
"We pride ourselves on being a hotbed of colonial history and Maori culture, which is as much a part of our identity as our love of the arts and beautiful environment," she said.
"Visitors love our region for the comprehensive experience it gives them of New Zealand's historic, cultural, creative and natural essence, and we love to show it off to them....We're hot to trot, and the best place in the world to live, work and play."