Chaotic spring weather is being forecast for the Bay of Plenty as air pressure systems battle it out in the skies.

WeatherWatch.co.nz forecasters say this month will be a wild mixture of weather with gales, warm days, cold days, snow and sunburn throughout.

'We're seeing plenty of high pressure around Australia, some monster highs, but they are mostly missing New Zealand and instead helping to fuel these strong winds that are surging up and down the country.” says head weather analyst Philip Duncan.

Water spout spotted at the Tauranga Harbour entrance, looking out towards Motiti. Photo: Graeme Butler.

Tauranga resident and Swim With Dolphins owner Graeme Butler captured this water spout on Tauranga Harbour on Monday during strong winds.

Strong winds are also driving in heavy rain and showers to the west while many eastern areas enjoy sun.

Philip says the UV index is climbing and already at 'moderate' levels for many regions despite the middle of summer still four months away.

'October often sees a spike in the unsettled weather with November often showing signs of calmer conditions and more settled patterns as we head towards the start of summer.”

A heavy rain was issued this morning for the Bay of Plenty and Rotorua with the heaviest falls expected in the west with 20 to 30mm of rain predicted.

Philip says one positive about the windy weather is it's keeping damaging and costly frosts away from orchards at this critical time of the season.

Despite the incoming cold change for the South Island, and some exposed North Island centres, a potent Tasman Sea low quickly formed over the weekend and brought more rain, wind and mild northerlies to northern and western regions late Sunday and into Monday and Tuesday.