It's the period of the year that's normally the coldest - but given the mild conditions New Zealand's been enjoying this week, you wouldn't know it.
The warm weather is likely to drive an early change in seasons, according to WeatherWatch, which is forecasting more dominant high pressure systems arriving on our shores in the coming weeks.
Head forecaster Philip Duncan says New Zealand is capable of wintry blasts right through until October, but warns time is fast running out for set-in winter weather.
He believes an "early spring weather pattern" is noticeable already, well before its respective meteorological and astronomical start dates of September 1 and September 23.
"Mother Nature ultimately dictates the start and end of winter and right now it looks as though an early spring is developing," Duncan explained.
"Spring is not summer, snowstorms and frosts can be more problematic in spring, but weeks of cold weather we had in June and July - especially the South Island - are now being replaced by warmer than normal airflows."
He believes this early spring pattern has been brought on by warm sub-tropical winds over the last fortnight, as well as a series of "wussy" southerlies that don't compare to the frosty conditions August has brought in previous years.
"Winter is about death and decay, but spring is about injections of warmth, grass growing faster, new life showing up in the form of buds on trees and lambs in paddocks," Duncan said.
"The warmer than average weather is helping kick some of this off."
In saying that, colder, wetter conditions are anticipated to make landfall in New Zealand over the next few days. NIWA is warning of showers and potential thunderstorms in both islands on Friday, snow in the south on Saturday and "a cold, frosty morning" on Sunday.
MetService says it'll be a departure from the high pressure that's dominated across the last few weeks.
"The pattern shifts from dry and settled to wet and cool as a low from the Tasman Sea and its fronts move up the country," a post on its Facebook page reads.
"Perhaps the biggest change will be felt by those in the lower North Island when the front moves across the island [on Friday], bringing a rainy end to what's been two weeks of unseasonably calm weather.
