Weather: Deluge of rain and heavy fog blanket North Island

Auckland's wet weather on Sunday forced the cancellation of the Big Gay Out for the first time in 18 years.

The lower North Island was blanketed in fog but parts of the South Island enjoyed blazing sunshine.

Organisers had promised the LGBT pride event would go ahead rain or shine, but the deluge was so intense health and safety became the big issue.

"[There were] obviously a large number of power concerns. We couldn't activate the main stage," Big Gay Out executive director Jason Myers told Newshub.

"Our primary concern was to take care of people, so unfortunately we had to cancel the event."

Bedraggled revellers were disappointed but philosophical, with one pointing out, "You really can't play with the nature... so I'm feeling really bad for it."

Many instead prepared to head undercover for an early after-party at a K Road bar.

"Normally there'd be 15,000 people at this event but the numbers were well down even before the announcement," Mr Myers said.

Several roads in central Auckland were flooded, at least for a few minutes.

Meanwhile rain wasn't the problem in the south of the North Island, where fog forced the delay or cancellation of many flights.

Fleur Douglas has to wait overnight to send her 14-year-old daughter from Wellington to Melbourne.

"You could tell the fog was just thick as pea soup, so yeah we've just been waiting for some kind of update, the boards haven't been helpful," she told Newshub.

Rapper Macklemore's fans were kept waiting after his flight to Wellington was redirected and he was forced to drive from Palmerston North for Saturday night's concert.

His support act couldn't perform, but Macklemore himself made it in the nick of time.

In the South Island, the West Coast's wild run has continued. Another drenching has caused a slip which has again closed State Highway 6 near Franz Josef.

Luckily for much of the east of the South Island, it was dry and sunny.