Flooding in Porirua as the Wellington region is hit with heavy rain.

Porirua is bearing the brunt of a torrential downpour in the region, with at least five schools closed and many streets drenched in surface flooding.

Porirua workers who can stay at home were advised to do so today because of surface flooding in the centre of the city and surrounding areas, Porirua City Council spokeswoman Maggie Tait said.

There are reports of flooding in Elsdon, the central city, Titahi Bay, Waitangirua and Cannons Creek.

VIRGINIA FALLON/FAIRFAX NZ There has been heavy flooding near Porirua School.

Five Porirua schools are known to have closed due to flooding.

They are: Porirua School, Porirua East School, Maraeroa School, Mana College and Paremata School.

All roads in Porirua have now reopened, including State Highway 58, the NZ Transport Agency posted on its public facebook page.

1 of 8 VIRGINIA FALLON/FAIRFAX NZ Vehicles drive through flood waters in Porirua. 2 of 8 SUPPLIED Flooding at Maraeroa School in Porirua. 3 of 8 ROBERT KITCHIN/FAIRFAX NZ People got caught out by the rain along Wellington's Lambton Quay. 4 of 8 ROBERT KITCHIN/FAIRFAX NZ It was a bleak day even from the safety of dry public transport. 5 of 8 TOM HUNT/FAIRFAX NZ A student wades through flood water near the Basin Reserve. 6 of 8 ROBERT KITCHIN/FAIRFAX NZ Pedestrians in central Wellington broke out their wet weather gear for the first time in a long time on Thursday. 7 of 8 VIRGINIA FALLON/FAIRFAX NZ There has been heavy flooding near Porirua School. 8 of 8 KATIE CHAPMAN/FAIRFAX NZ Wellington's Lambton Quay is flooding as heavy rain hits the capital on Thursday

Is there heavy rain or flooding in your area? Send your photos and videos to newstips@stuff.co.nz

At Maraeroa School, near Porirua College, the reception area and junior classrooms flooded early, principal Kathleen O'Hare said.

MetService MetService Severe Weather Warning Thursday 5th May

The school remained open for several hours in the morning, though parents who had rung to check were told to keep their children at home, but the school was closed by 11.30am.

O'Hare said children were "quite oblivious to water coming into the other side of the classroom," during the morning.

The fire service were called in the hope it could pump water out of the rooms, O'Hare said.

"The water is almost up to the office desk, it's 3-4 metres into the admin area."

She expected the flooding would cause some damage, though staff had tried to move things off the ground.

Porirua College, Tawa College, Titahi Bay Intermediate and Bishop Viard College all remained open.

The Fire Service has responded to multiple callouts in Porirua with surface flooding in many streets.

IN THE CAPITAL

Wellington City Council responded to about 24 flooding related jobs before 10am.

Kilbirnie, Tawa, Lyall Bay and near the Basin Reserve were the hot spots, council spokesman Clayton Anderson said.

"We have contractors out but if people spot potential flooding and can clear the drains safely themselves then that would help the situation."

He said that because Wellington had been dry the autumn leaves had been falling, but were now being washed into drains causing the problems.

Cobham Court is closed due to flooding, please steer clear. pic.twitter.com/hKgLQUFwFL — Porirua City Council (@Porirua_City) May 4, 2016

Calls have come in about flooding in areas including Rugby St, near the Basin Reserve, Wadestown, Cuba St, Lyall Bay, Hutt Rd, and Newtown.

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MetService issued a severe rain warning for northwest Nelson, Wellington, Horowhenua and Kapiti as a complex trough crosses central New Zealand on Thursday morning.

A warning was issued that streams and rivers were likely to rise rapidly and slips were possible.

"For Wellington, after such a prolonged period of dry weather, surface flooding is possible as drains may struggle to cope with the short duration heavy rain and an influx of autumn leaves," MetService's warning said.

A wet day for the capital, Kapiti, & parts of the upper South Island tomorrow. https://t.co/Yjbq0jxdqz ^CL pic.twitter.com/oZTRa8Uyrv — MetService (@MetService) May 4, 2016

Between 7am and 1pm on Thursday in Wellington, up to 60mm of rain was expected, with up to 25mm in an hour.

Tawa had 20.4mm of rainfall between 8am and 9am this morning, meteorologist Claire Flynn said.

The rain was unusually heavy, Flynn said.

"Usually we say 6mm of rain in one hour is heavy and they have gone well beyond that."

Flynn said the weather arrived due to a front that was sitting over the region.

In Horowhenua, Kapiti and the Tararua ranges, heavy rain was expected to ease this afternoon. Up to 90mm of rain was expected between 7am and 3pm, with up to 25mm per hour.

In the ranges northwest of Nelson, up to 30mm could fall between 7am and 9am on Thursday.

It's about time it rained. Plants need watering. So do your socks. May the 5th be a #wet one. #Wellington #soggy — Taranaki St Puddle (@TaranakiPuddle) May 4, 2016

Surface flooding was made more likely as the ground in the Wellington region had become hard after a long period of warm, dry weather, Flynn said.

The rain was easing and moving north by midday, heading for Horowhenua and the Kapiti Coast, MetService communications meteorologist Lisa Murray said.

"The heaviest stuff has moved off Porirua, they just have a few showers left.

"It will slowly move north but we're not expecting the same accumulations."

The capital would remain muggy throughout the day, following another hot night with temperatures already sitting close to the expected high for the day – 18 degrees Celsius – at 8am.

While the wet weather would continue through Thursday, the front was weakening and cloud was expected to clear by Sunday, making way for a fine end to the weekend.

Further North, Auckland was in for a cloudy day with a few showers in the afternoon.

Adams said the country's largest city would have another warm, muggy day with a high of 22C.

Things were looking better down south, with a ridge of high pressure sitting over the South Island.

Christchurch was in for a high of 19C on Thursday, with the city becoming fine in the afternoon. Ashburton is in for much of the same, with a high of 18C.

Over on the West Coast, Greymouth and Hokitika can expect highs of 18C, rain clearing in the morning, then fine skies.

Adams said the high temperatures spread across the country were unusual for this time of year.

The average maximum temperature for May was about 16C, so New Zealand was tracking towards a record-breaking month.