Christmas Day weather looking good, but a chance that may change - NIWA

Christmas Day weather is looking okay right now, but there's a good chance that could be changing soon, according to NIWA forecaster Chris Brandolino.

The start of summer has been marred by downpours and thunderstorms, mixed with the occasional bout of pleasant weather.

Now there's Cyclone Owen to worry about, which has re-formed off the coast of Australia and could bring its tail to New Zealand.

Forecaster Weather Watch warned New Zealand should be prepared for heavy rain and wind and Mr Brandolino told The AM Show NIWA he isn't discounting it either.

He said NIWA was keeping an eye on it in case it made its way to NZ in January.

But what everyone wants to really know about is the Christmas Day forecast, which Mr Brandolino said may fall victim to the season's changeability.

"We're going to have another change to colder temperatures about Wednesday of next week, that's probably going to last into the weekend, the week before Christmas," he said.

"Then things should start coming around around Christmas Eve, Christmas Day. I am a little concerned that a front may try to move on through around Christmas Day.

"Look, these things, it's all about timing, you can take five days - in that five day period could be overall bad in terms of weather but you'll still find one good day, where does that one good day sit?"

The week may not be looking fantastic either, with Mr Brandolino cautioning sportsreader Mark Richardson against turning on his home irrigation system.

"For the next few days, you probably don't want it on."