The cold air moving up NZ will be locked in by an incoming high pressure zone – meaning frosts are likely across a number of regions overnight tonight.

The main risk zone will be the South Island where high pressure is expanding, while the North Island will have more wind, rain and cloud to limit frosts to perhaps only around Central Plateau.

Temperatures tonight in the South Island may well go below -5 in some alpine communities and for lower lying areas -1C to -3C is expected.

We have worked hard to try and make it easier to see upcoming frost risks and have two ways you can see the risks:

1) The NZ Frost Forecaster at www.RuralWeather.co.nz has a special Frost button top of the page and this not only shows your very local area (or anywhere in NZ you choose) but it also displays it in graph form to show you where the real frosts risks are. This is currently FREE to access so please check it out.

2) If you visit WeatherWatch.co.nz we have Below Zero Maps which show, in purple shading, the areas going below zero tonight. We’re working on enhancing these maps later this year to also include frost risks for those places not technically going “below zero” but near enough for a frost to form. These maps are also currently FREE to access and you can view them here.