Other North Island areas not under the heavy rain watch can expect scattered rain, with the scattered rain to hit the lower North Island, Wairarapa and Wellington, tomorrow.
The weather will then ease to showers on Boxing Day.
But it looks a lot more promising in the South Island. The worst they will get is a few isolated showers and low cloud but there will be fine breaks on Christmas Day.
However, Queenstown, Wanaka, Alexandra, Buller, Westland could reach temperatures as high as 28 or 29 degrees.
"If there's going to be any showers they're going to be isolated."
Marintchenko said her place to be for Christmas Day was Queenstown.
CHRISTMAS TEMPERATURES
Christmas Eve Christmas Day Boxing Day
Auckland 22 25 24
- Wet, warm and humid at night.
Hamilton 21 24 26
- Wet, warm and humid at night
Tauranga 22 24 27
- Wet and warm at night
Wellington 23 22 20
- Inland areas, ie Upper Hutt, can expect warmer temperatures
Christchurch 20 22 19
- Low cloud with fine breaks, fresh northeasterlies kick in Boxing Day
Dunedin 21 23 17
- Cloudy with fine breaks before cooler Boxing Day weather