A brief southerly on Friday will drop temperatures by several degrees bringing heavy frosts into Saturday morning for the lower inland South Island.

Coldest areas will be inland Southland where overnight lows will go from +3 tonight to -4C on Friday night. With showers around over the next 24 hours this may lead to black ice on some roads on Saturday morning.

The frosty weather heads northwards too, but won’t be as intense with Canterbury up to the lower North Island in the “possible” frost zone, but not locked in.

There are two ways for you to check Frost conditions in your area:

1. Use our hyper-local Frost Forecaster at www.RuralWeather.co.nz (powered by IBM)
2. Use our interactive Below Zero Maps here at WeatherWatch.co.nz.
   

The cold change is shorted lived with west to north west winds arriving at the weekend in the South Island, lifting temperatures.

In fact, parts of Southland have a Daytime High of just +8C on Friday but it springs back up to +17C by Monday!