Stand by for a wetter spring than usual

Don't pack away the brollies, raincoats and gumboots yet, as spring is likely to be slightly soggier than normal.

Climate scientists are forecasting normal to above normal rainfall for most of the country, with slightly warmer temperatures because of more northerly quarter airflows.

The only worry is the South Island's east coast which, because of a dry winter and a prediction of only normal rainfall, is likely to have below normal soil moisture levels and stream flows - potentially affecting crops.

Niwa senior climate scientist Jim Salinger said that spring was likely to be 0.5C warmer than normal.

There would be cold days, but there would also be warmer than normal days to look forward to, said Dr Salinger.

Auckland's average October temperature is forecast at 14.5C, rising steadily to 18C in December. The trend is reflected throughout the country.

"Last spring we had very strong sou'westers, and it was cold. December was incredibly cold," said Dr Salinger.

He expects spring rainfall to be between the average and 20 per cent higher for the North Island and the top half of the South Island.

Niwa hydrologist Charles Pearson said the higher rainfall was expected to top up river levels, which were slightly lower than normal because of a dry September.

The only exception is coastal Canterbury and East Otago, which are predicted to receive only normal rainfalls while experiencing above average temperatures.

Mr Pearson said the region's low rainfall for this time of year would not be enough to raise stream flows, despite being aided by snow last month.

Rivers in the South Island's east coast were flowing at less than 25 per cent of normal.

"It's obviously not normal, but it's not as bad as it could have been."

At best, rains could keep river levels steady, he said. If levels fell drastically, the regional authority would have to restrict crop irrigation..