Warm autumn weather set to roll on into winter

Autumn in Tauranga was warmer and wetter than usual and the trend looks set to continue through winter.

The mean temperature in Tauranga during the autumn months was 17.1C - 1.4C above average. Rainfall was 29 per cent higher than usual with a total of 423mm of rain, according to interim statistics provided by Niwa as at May 29.

Rainfall in Tauranga was 8 per cent above normal during the last month and the temperature was 1.1C higher than it usually was during May.

The temperature might have plunged during the past week but it should not drop much lower, Niwa climate, variability and change principal scientist Brett Mullan said.

A mild winter was predicted for most of the country but rainfall was likely to be above normal in the Bay of Plenty.

"The main picture is, we're expecting a bit more winter activity in the north Tasman bringing a bit more warm air than usual over New Zealand."

As the Bay of Plenty is exposed, much of the weather from the north is likely to hit the area, he said.

The temperature is expected to be about 0.5C above the typical winter temperature, he said.

"Half a degree might not sound like much but it will be noticeable at the shoulder ends of the season spring growth might come through earlier or the grass might grow a bit longer."

But with the warm weather came the likelihood of more rain, Dr Mullan said.

"The fact that we expect more fronts from the north means we expect more rain. It might not be sunny if you're getting weather systems from the north it might be a bit cloudier but still warmer."

Weather Watch analyst Philip Duncan said the weather during winter looked likely to include a bit of everything as it had during autumn.

"My feeling is that we're in the same weather pattern that we've been in for the last two years, which I would class as a chaotic one that's opposed to El Nino or La Nina, which is quite predictable."

The fact Tauranga was in the midst of a drought at the start of autumn but had higher thanaverage rainfall by then proved how chaotic the weather pattern is, Mr Duncan said.

The weather during May was likely to continue during June, he said.

"I think this winter will be no different to last year or the year before. There's no consistent weather pattern. It makes it hard to predict except to say it's unpredictable."

Tauranga by the numbers

• 
  119mm of rainfall from May 1 to 29 8 per cent above average.
• 
  14.4C mean temperature from May 1 to 29 1.1C higher than usual.
• 
  423mm of rain during the autumn months 29 per cent above average.
• 
  17.1C mean temperature during the autumn months 1.4C higher than usual.