"We have actually got watches out for the upper North Island, but Hawke's Bay is not in the watch at this stage."
Today is expected to be wet, with periods of rain throughout the day, as well as possible heavy rain.
"That's kind of the story for Christmas Day as well, just periods of rain and heavy rain right across the region.
"Maybe the evening of Christmas Day we might see the rain ease somewhat, and just have a cloudy evening.
"But you'll probably have to wait until Boxing Day before you get to see any decent sunshine."
Despite the wet weather, it will be warm, Napier and Hastings getting to 22C and 21C today respectively, and 24C and 23C on Christmas Day.
For those travelling for Christmas, the further south you go the better, Millward saying Queenstown and Wanaka are looking to be the exception, each hitting around 30C.
He said keep up to date with the forecast, and stay safe if travelling on the road.
"Keep up to date with all the severe information, and if you are travelling out on the roads just stay safe while you are driving a drive to the conditions."