A polar jet stream is set to bring a chill across most of the country in coming days, including more snow for the South.
Crown agency Niwa said autumn "is ending as it started - with below-average temperatures".
It said a southerly change would usher in colder air over the weekend, which "will begin a period of gusty, brisk wind for parts of the country, making it feel even colder".
"Sunday looks to have a wind chill across most of the country which may be reinforced toward the middle part of next week."
The news comes after a cold front hit the country last weekend, bringing snow to many parts of Otago, Southland and South Canterbury
MetService is predicting snow for parts of the South across the weekend and into Monday, saying it could lower to 400 metres on Sunday.
The forecaster said a burst of southwest winds arriving in the second half of Saturday would also bring an increased risk of severe gales around the southeast coast of the South Island.
"This risk lasts through the weekend but generally winds ease off a bit as we enter next week," MetService meteorologist Lewis Ferris said.
“An extended period of strong wind from the same direction is a sure-fire way to generate large waves and energetic, long period swell.
"The coastal conditions look to worsen through the weekend and some areas will continue to see big waves into next week,” Ferris said.
He said most of the country should expect below-average temperatures, and warned people to prepare for the wind chill.
Niwa said milder temperatures were forecast heading into June, as the "polar jet" was expected to calm down.
With the El Niño pattern ending, "its influence on the jet stream patterns is expected to wane", Niwa said.
Winter was likely to bring more westerly or northwesterly winds - "a stark contrast to autumn's chilly southwesterlies".
- ODT Online/RNZ
