"We are still full and look to be for the rest of the week."
Waihi Beach Top 10 Holiday Park proprietor Ian Smith said overseas visitors turning up at the door without a booking had been sleeping in their vans on the roadside because there was nowhere to go.
"We will see them come back in now, so you are more likely to get a booking if you plan a week ahead."
The situation is similar in Northland where only a few of the most popular camping spots still have space available.
At Kerikeri Top 10 Holiday Park, manager Louise Smart said campers pleased with the weather wanted to extend their stay.
"It's been full all [through] Christmas and only three or four sites with power are available through to January 20," she said.
"We had a family group of 19 roll up at 7pm - with a tent site we can usually squeeze them in but the ones who are chancing it can miss out on a power site."
Bay of Islands Holiday Park is 60 per cent full on tent and campervan sites and fully booked for cabins for the next fortnight.
At Ninety Mile Beach Holiday Park, 18km north of Kaitaia, proprietor Dave Armistead said: "We are still chocker until January 20 and anyone after a tent site will have to book."
Camp Waipu Cove is fully booked and at Ruakaka Reserve Motor Camp powered and tent sites among the 320 offered are usually taken by late afternoon.
North of Warkworth, the Whangateau Holiday Park is heavily booked until next Sunday but a few camping sites are still free.
But the flood of campers isn't restricted to Northland and the Coromandel.
In the Central North Island, Turangi Cabins and Holiday Park has had more demand this year for tent sites for big family groups of up to 64 people.
In the Bay of Plenty, Papamoa Beach Top 10 Holiday Resort general manager Rebecca Crosby said vacancies were filling up fast.
"I think it's due to the resurgence of the Kiwi camping holiday and the high standard of holiday parks' accommodation and playgrounds and beach locations."
More inquiries than usual for tent sites were received on the west coast at Raglan Kopua Holiday Park.
"It's nice to see it, like when I was a kid," said proprietor Mary Clark. "We can find them a handkerchief-sized site if they just turn up but I'd stress the need to book."