But according to meteorologist Thomas Adams there was good news too. The front would be shortlived, and the rain will peter out to make way for fine weather over the rest of the week.
"Basically the rain is for the South Island on Monday and the North Island on Tuesday."
Heavy rain was expected to hit Kapiti and Wellington, where the forecast high is 19C.
"It's only a watch at this stage, but it could be upgraded to a warning," Adams said.
Similar was expected for the Bay of Plenty and further north to Auckland and Kerikeri.
Auckland's Boxing Day Races looked set to go ahead this morning, although Fashion in the Field contenders might want to accessorise with an umbrella to protect their outfits.
Further south, Bayleys Pirongia Boxing Day Races in Waipa have been cancelled because of the rain.
In a post on the event's Facebook page it said the cancellation was for the safety of riders, drivers and horses.
Adams said the showery weather would clear to make way for a sunny few days but the end of year luck wouldn't reach all parts of the country.
"Gisborne, Hawke's Bay are the exceptions," he said. "They will hold on to the showers. That rain will stick around that region for the next few days."
Adams said it was a little early to knowthe best spots to be for New Year's Eve.
Another front could move in to dampen festivities, though it wouldn't have as much of an effect as the one moving across the country now.
"This is the last major thing that will affect New Zealand for this year."
The system meant a soggy Christmas Day for southern regions yesterday, although in spots like Canterbury the rain was paired with soaring temperatures.
Metservice recorded 30.9C at the airport, topping the previous Christmas record of 29.6C.
The area would experience a drastic drop in temperatures overnight, and would only reach a high of 16 today.
Gates were due to open at Hagley Oval at 9.30 for the Blackcaps vs West Indies ODI. The match was due to start at 11am and spectators would likely see a few bouts of rain.
Many parts of the country enjoyed a similarly fine Christmas Day, interrupted by isolated showers in central and western areas.
The warm weather kept surf lifeguards busy. Around the country they were called to rescue 17 swimmers yesterday.
Of all the sandy hot spots, there had been a spike of rescues at Karioitahi Beach in the south of Auckland. One person burned their feet on the sand and another fell on rocks.
Mt Maunganui Beach had also been busy. Further south, Fiordland was under a heavy rain warning yesterday morning and a severe thunderstorm watch was lifted just before 11am.
Southland, West Coast, and Otago saw rain early on as the front moved up the country with rain to fall in Canterbury and Marlborough last evening.
Boxing Day forecast
Whangarei: 26C with cloudy periods and a chance of showers.
Auckland: 24C with occasional showers and possible thunderstorms in the afternoon.
Hamilton: 24C paired with the odd shower and the possibility of thunderstorms from midday.
Tauranga: 24C with frequent showers and a chance of early evening thunderstorms.
Whakatane: 23C showers likely to be frequent in the afternoon but will clear at night.
Rotorua: 21C with showers likely as well as thunderstorms heading into the evening.
Taupo: 22C with bouts of rain, thunderstorms likely in the afternoon as well as northerlies.
Napier: 27C with occasional rain, possibly becoming heavy in the afternoon.
Gisborne: 26C cloud thickening with rain developing into the afternoon.
Palmerston: North 22C a few showers expected, especially around midday.
Wellington: 19C showers likely on and off all day.
Christchurch: 17C with increasing cloud, occasional rain developing late.
Dunedin: 23C morning showers clearing to fine spells.
Queenstown: 16C the odd shower, turning into a fine afternoon.
Source: MetService
