Holidaymakers and triathletes who battled rain and gusts in Auckland and the Waikato-Bay of Plenty yesterday can expect better weather today, although the Far North is likely to be wet.

The MetService says today looks like being overcast but mainly dry in Auckland, with much lighter winds than the 74km/h gust that hit Bean Rock lighthouse in the Waitemata Harbour yesterday afternoon.

That was after the Barfoot & Thompson grand final of the ITU world triathlon series in Auckland, in which participants slogged it out in wet and muggy conditions with the temperature reaching 19C.

About 13mm of rain fell on Auckland, and about 22mm in the Waikato as what forecaster Nic Bonette called a "tongue" of warm air swept over the two regions from the northwest.


That dampened the fun for holidaymakers such as Brian Riley of Warkworth, who cut his losses by packing up a drenched tent before taking refuge in a cabin at Raglan's Kopua Holiday Park.

Ms Bonette said Auckland was likely to be just cloudy today - welcome news for competitors in the age-group triathlon to be held on the city's waterfront this morning and the paratriathlon event starting at 3.15pm.

But she expected rain in the Far North and isolated showers through the Waikato and Waitomo areas.

The Waikato was also hit by lightning yesterday, and there were some isolated strikes near Auckland too, although mainly out to sea.

Auckland Blues rugby player Alby Mathewson tweeted that his plane was struck by lightning on its flight from Wellington, where his team played on Saturday night in the ITM tournament semifinal.

MetService analyst Ian Gall warned travellers in the South Island that some alpine roads - Lindisto Lewis Pass, Porters Pass and Arthurs Pass - might be closed this morning.

He expected temperatures to drop across the South Island overnight, although those in the North Island would remain stable at between 16C and 18C.

The MetService is predicting a high of 18C for Auckland, offering only slight relief to triathletes from yesterday's 19C. But the temperature is expected to ease to 16C tomorrow as the start of a short working week sees the wind changing from northwesterlies to southwesterlies.

Gale warnings for the south have meanwhile been lifted after gusts of more than 120km/h were recorded in Wellington in the past day or so.