The easing weather conditions will also come as a relief for stranded passengers after dozens of flights were cancelled in many parts of the country.
Lynn Clayton spent last night in a Queenstown hotel after her flight home to Auckland was cancelled.
She described a chaotic scene at Queenstown Airport saying there were "queues are from one end of the airport to the other" and how parents with children and international travellers were left stranded, possibly for several days.
"It could be two or three days, there's such a backlog and there are no seats available because it's the end of the school holidays. If they can manage it they will put another flight on (today) but they need to have staff and crews available in the right places to do that - they are not sure.
Further north Kristy Rutherford and her family drove through a severely flooded rural Canterbury road with water at times lapping at the car windows.
The Tauranga family had been visiting family in Geraldine and were travelling to Christchurch airport when they encountered the flooding on Thompson's Track.
"It was incredible. I've never seen anything like it before, ever," she said.
A severe weather warning for Canterbury and Otago, which bore the brunt of heavy rain and gales yesterday, would remain in place until midday.
Metservice forecaster Larissa Marintchemko said there would likely be snow down to 600m in Otago today,
She said there would still be showers and periods of rain in the North Island today but rain was expected to ease in all parts of the country this afternoon.
NIWA said Oamaru surpassed it's wettest July on record with 57.6mm of rain falling between 9am and 5pm. The previous record stood at 56.1mm - in July 1974.
Timaru recorded more rain - 46.4mm - in an eight hour period yesterday than it typically receives in the entire month of July.
The North Island was spared the worst of the rain and flooding, although Auckland was affected by hail and thunderstorms.
Floodwater lapped at car windows
Desperate to catch a flight, Kristy Rutherford and her family drove through a severely flooded rural Canterbury road with water at times lapping at the car windows.
The family from Tauranga had been visiting Rutherford's father-in-law in Geraldine and were travelling to Christchurch airport when they encountered the flooding on Thompson's Track.
"It was incredible. I've never seen anything like it before, ever," she said yesterday.
Pretty much the entire length of road, which connects Geraldine and Rakaia, was flooded, with the water varying in depth from just touching the car's undercarriage to up to the windows. "A truck in the distance, the water was actually up to its lights."
The car the family was travelling in was her father-in-law's Lexus, which could have its cab raised so they were able to make it through the flooding easily enough, but others weren't so lucky.
Two other cars had become stuck in the floodwaters and were being towed out by some farmers, Rutherford told the Herald.
"It was quite freaky really, actually. I mean if you got stuck there there's not a lot around."
She said they were waving at other drivers to warn them to turn back if possible.
But Rutherford's kids, aged 4 and 13, were thrilled rather than scared by the unusual sight. "There was water splashing all over the windows, they found it extremely exciting."
The journey took about three hours, an hour longer than usual, and the family made it to their flight just in time. "We had used a bit of common sense and decided to leave an hour earlier than we planned to, which was fortunate.
"We flew in a little plane so we thought it was going to be quite a bumpy ride. But it wasn't too bad actually."
They're now back home and are happy to be warm and dry.
"I think we got out at a good time," Rutherford said.
- additional reporting Brittany Keogh
