Heavy rain resulted in dozens of callouts to slips and flooding around homes in Wellington overnight.
Most roads closed by slips had reopened this morning but more wet weather is expected to drench most of the country today.
Inspector Marty Parker said Akatarawa Rd in Upper Hutt would need to be cleared of debris this morning but its closure was unlikely to have an impact on peak-hour traffic.
Some centres had received more than 50mm since late yesterday, WeatherWatch.co.nz said.
Wellingtonian Adam Woollett said he could tell the burst was coming.
"You know when it's going to happen, it happens at the end of summer when you get the first big rain," he said.
"It just pisses down."
Woollett said it was the first major rain for a couple of months for the capital, where it had been "ridiculously hot and sunny" up until now.
"You know [the flooding] is going to happen because all of the drains are to be blocked with dry leaves."
A Tawa resident told nzherald.co.nz he woke to a garage flooded in one metre of water that included sewage.
He said he couldn't save much in his garage "because it was already 20-30cm deep by the time we realized" it was happening.
The last time it happened was 2.5 years ago.
Meanwhile, parched eastern regions of the North Island are expected to receive the most rain today.
"Even though some predicted heavy falls haven't really come into being here in Christchurch, any rain has been welcome at this point," WeatherWatch analyst Richard Green said.
"More [showers] can be expected off and on this morning before skies clear and then another week of dry conditions are likely."
Waitangi Day is expected to be "largely sunny" across the country.
Mr Green said there was still a risk of a few showers across Gisborne and northern Hawkes Bay and the chance of a shower in the Far North.
Temperatures are expected to slowly climb to normal February levels from tomorrow after a chilly start in the south where temperatures have dropped to single figures.
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