A new venue and new technology will add an element of uncertainty to the second round of the SailGP which will be raced on Auckland's Waitemata Harbour.

Wet weather is forecast to hit the North Island, with rain set to sweep across the top of the country on Saturday.

The weather is set to be mostly fine for much of the country, including Auckland which faces an action packed weekend.

In a post on Facebook the festival organisers told ticket holders to check their emails, and that five working days should be allowed for refunds.