People in the top half of the North Island are being told to prepare for more intense rain as Christmas day approaches.
MetService has issued a heavy rain warning for Northland, Coromandel Peninsula, and a watch for Waikato, Bay of Plenty and Gisborne.
"If you're driving around please take care, there's potential with some of the intense rainfall to cause some surface flooding maybe even flash flooding" - Meteorologist Andy Downs
Meteorologist Andy Downs told Summer Report the forecast was far from the festive weather people would be hoping for.
"People in all those regions, which also of course quite popular tourist spots at this time of the year, people need to be prepared for some fairly intense rain."
He said motorists should also take caution as the intense rain created potential for surface flooding and flash flooding.
"The areas of concern are eastern parts of Northland, northern parts of Auckland but particularly Coromandel, Bay of Plenty and maybe even those northern parts of Gisborne, where we could see a further substantial amount of rain over the next 24 to 36 hours."
Mount Maunganui's base track has also been shut until further notice due to slips and debris.
Tauranga City Council said at this stage all other tracks on the mountain were open.
Early this morning, about 150 campers at two Bay of Plenty holiday parks were evacuated because of flooding.
Emergency services were called to the Waihi Beach and Beach Haven Top 10 holiday parks just before 3am.
Police said campers were evacuated and taken to the Waihi RSA.
There were no reports of injuries.
Ian Smith, who runs both camping sites, said the flooding has cut some Christmas holidays short.
"There's a lot of kids who were hoping to spend Christmas Day here tomorrow and Mum and Dad have said no. There's still rain on the weather radar so they're a bit concerned about that," Mr Smith said.
Campers were evacuated to the local RSA as a precautionary measure but have since returned.
"At daylight they returned and have started to clean up their tents. Some of them obviously didn't stand up to the rain so well. Some of them have made the decision to go home early, others are soldiering on," Mr Smith said.
MetService expected the severe weather to spread south across the North Island between tonight and tomorrow, bringing periods of heavy rain and possible thunderstorms to the northern districts.
The heaviest rain is expected in Northland and Coromandel Peninsula.
"We've already seen over 90mm of rainfall at Tauranga Airport this morning, it has eased and there's a bit of a respite there but as I say there's more rain on the way," Mr Downs said.
However, Mr Downs said there was possibly some relief for those at the top of the North Island tomorrow.
"This main rain band we're talking about is going through today - Christmas Eve - particularly overnight and early Christmas morning but later through [tomorrow] morning the main rain band will clear and the top of the North Island might actually start to see some sunshine but it will be mixed with showers and possibly even some thunderstorms."
On the other hand, the lower part of the South Island looked like the best place to be for Christmas with Central Otago enjoying some sunny skies today.
The outlook for New Year's Eve at the moment predicted some strong westerly flows and possibly showers in the west but the eastern areas looked good, Mr Downs said.