Campers at the Waihi Beach Top 10 Holiday resort were evacuated on Sunday morning after a nearby river breached its banks in several places.
The campground was inundated and tents, campervans, and buildings were swamped, affecting about 150 people.
But yesterday offered a reprieve. Receptionist Megan Smith said some of the campers who were evacuated had returned to their camping spots after waking up to sunshine on Christmas Day.
MetService meteorologist Tui McInnes said yesterday there were many lightning strikes developing across the North Island.
"The front that brought the rain [on Christmas Eve], that has moved south ... If you saw a satellite maybe you would see a wonderful koru-looking-like cloud, it's spiralling out."
Auckland was treated to bucket-loads of rain yesterday, leaving parts of Kaipara, Muriwai, Warkworth and Upper Waiwera without power in the morning.
Boxing Day weather
Whangārei: Fine apart from morning cloud. High 24C, Low 15C.
Auckland: Morning cloud, then fine. Fresh southwesterlies. H 23C, L 16C
Hamilton: Fine apart from morning cloud. H 26C, L 12C
Tauranga: Mainly fine, with an afternoon shower or two. H28C, L 15C
Wellington: Cloud and a few showers, then long fine spells. H 19C, L 12C