A forecaster warns August is a "highly unstable month weather-wise" with the chance of surprise storms and snowy blasts.
WeatherWatch's climate outlook predicts the upcoming month will lean warmer and drier than average - but large lows and storms will remain over the Southern Ocean.
August looks to start off on a colder note as large lows remain south of Australia.
"This will 'spill over' into the New Zealand area dropping temperatures and encouraging the chances of some severe weather in NZ (severe gales, heavy western rain, some snow higher up)," WeatherWatch predicts.
After this, week two of August sees an "evening out process" with large storms - normal for August - in the Southern Ocean and a powerful extra-wide high pressure zone moving out of Australia.
As this moves into the north area of New Zealand, it will encourage fairly mild westerly winds to blow over the country.
Then week three kicks off with a fading southerly and a high potentially moving in.
"If this strong high does roll in it may bring a frosty period of weather, followed by milder northerlies," WeatherWatch states.
These highs will have an impact on rainfall too, with rain events coming off and on from the west while it remains dry in the east.
"While the first week or so of August may be wet on the West Coast, the entire month may lean drier than usual - suggesting the forecast highs may well come in."
