Unseasonably cold weather is due to lash New Zealand, especially the South Island, in the weekend and into early next week.
Temperatures in Christchurch are set to plunge from 23 degrees Celsius today to around 11 degrees on Monday.
Weather forecasters say the southerly storm could arrive in the south of the country, bringing some heavy rain, snow, cold winds and lower temperatures.
Lisa Murray of MetService says a low pressure zone to the east of the country will suck up cold air from Antarctica over the country.
"The farming community needs to keep a very close eye on the forecast and to start preparing," Ms Murray said.
In the South Island, snow levels could be as low as 400m to 500m in some places, and at 700m further north.
The storm is expected to hit on Sunday and then extend over the country possibly through to Wednesday. However, details could change in the next 48 hours.
MetService severe weather outlook warns that New Zealand could experience some heavy rain, even hail over the country with persistent rain over the east coast of the South Island and the lower North Island on Wednesday.
"With the rain come strong and very cold southerlies."
It said that snow could be as low as 400 to 500m in parts of the South island, and possibly about the North Island high country above 1000,. "Higher roads could be affected, and conditions might be hazardous for young stock."