Holidaymakers are being warned that remnants of Cyclone Evan will be passing through the upper North Island over Christmas, causing rivers to rise and making surface flooding possible.
MetService has this morning issued a severe weather warning for the northern parts of the North Island.
A deep low - which was formerly Cyclone Evan - would lie north of Northland tonight, then just west of Cape Reinga by the end of tomorrow, before drifting west of the North Island on Christmas Day, MetService advised.
Rain was expected to become heavy later this afternoon, and then continuing through Monday and into Christmas Day.
The weather warning meant northern parts of Auckland could expect up to 100mm of rain between 6pm tonight and 6am tomorrow morning. Rainfall could reach 30mm/hour with possible thunderstorms.
WeatherWatch analyst Aaron Wilkinson said the heaviest rain and strongest winds the weather system would produce would move into Northland tomorrow.
It would bring rain and strong gales to the upper North Island, with the heaviest rain pounding Northland, Auckland north of Whangaparoa, and the Coromandel Peninsula north of Tairua.
The low would track south on Christmas Day, bringing in humid cloud and the odd shower of drizzle patches. By Boxing Day the low would weaken and move east, bringing a period of rain to most.
MetService warned holidaymakers and trampers that rivers and streams could rise rapidly and that slips and surface flooding were possible.
The lower South Island could remain fairly dry.