Spring has hit with a sting in its tail, marked by Auckland Point School's annual homage to the season with a bee theme and a weather warning from the MetService.

The Nelson school's installation this year of busy bees among the daffodils on the Haven Rd reserve is a marked contrast to the mud and rain afflicting farms around the region, which is beginning to stress stock and tire farmers.

Growers and farmers said today they were not unduly concerned about the forecast cold snap as lambing and calving was either established or about to begin. Driving rain and freezing winds were a bigger problem, and it looked like Nelson would escape the worst of it.

The MetService said the major cold outbreak in the south would spread cold southwesterlies over all of New Zealand today. Snow is expected down to 500 metres or lower in eastern areas from Canterbury to Gisborne, around the central North Island high country and Wellington.

Nelson would be sheltered from the brunt of the weather, but was due to wake tomorrow to below zero degree temperatures, MetService media and communications meteorologist Daniel Corbett said.

"We're just seeing the first of the polar chill. The first front moved on to the far south and swept up the country last night, with a real southwest steer to it."

Mr Corbett said much of Nelson will be protected, but temperatures are expected to plummet once the wind drops and the sky clears.

"Wednesday will be the coldest morning but Thursday is not looking like a cup of tea either," Mr Corbett said.

Snow was reported falling on the Hope Saddle this morning.

St Arnaud farmer and immediate past chairman of the Beef and Lamb Farmers Council Malcolm McConochie said today their Lake Station farm was about a third of the way into calving and lambing had not yet started. Others in the area were another fortnight away.

"The season's been bloody awful though. We're all sick of the wet."

He said stock were getting stressed through not resting properly.

"Animals really only sleep properly when it's dry. They're spending a lot of time with their backs to the rain."

Mr McConochie said heavy frosts were not as concerning as cold, driving rain.

"We expect this sort of rubbish at least once during the spring, and we're well prepared.

"We've plenty of grass but the cows just need sunshine now."

Mr McConochie was expecting that to happen soon.

"My grandfather used to say you always get your averages - average sunshine and average rain. At some point it's going to get bloody dry."

Federated Farmers Nelson branch chairman Gavin O'Donnell said windchill was the killer for farmers and it looked like Nelson would be spared, but the continual wet conditions were making it difficult.

"It's really just par for the course. Farmers deal with wet, cold and drought and after this really wet period the tap will get turned off and by February we'll be praying for rain," Mr O'Donnell said.

Motueka Fruitgrowers Association president Simon Easton said growers were not concerned about forecast frosts as fruit trees were yet to flower.

"Another couple of weeks and I think it might have impacted on pipfruit."

Mr Easton said the biggest problem was the continual wet, which was making it difficult to get around.

Auckland Point School teacher Judi Hansen said they had initially thought about umbrellas as the theme.

"We have been doing bees as a topic, so bees it was."

A swan among the bees represents her "swansong" effort as she is retiring at the end of the year after 32 years at the school.

The weather is expected to be fine for the next couple of days, and then rain is forecast for later in the week as another northwesterly sets in.

Mr Corbett hesitated to say how summer was likely to shape up.

"So many factors affect it. It's like someone mixing a wedding cake and you think it's going to turn out beautifully but all you get is three cupcakes on a plate. Water temperature is what affects our weather, that's what makes the final ingredient to the recipe for summer."

- © Fairfax NZ News