Canterbury has been battered by heavy rain, with nearly 290 millimetres of rain recorded in parts of Banks Peninsula over the past 36 hours.

MetService meteorologist John Law said the rainfall totals were significant, especially given Christchurch would normally expect around 30 millimetres for the entire month of February.

“That’s a very significant amount of rain to come through in a relatively short space of time,” Law said.

Banks Peninsula has borne the brunt of the downpour, with widespread flooding reported in Akaroa and surrounding areas.

Law said another 70 to 80 millimetres of rain was possible through the day before conditions begin to ease.

“We’re going to keep hold of that heavy rainfall warning for those areas through into the evening today before things start to ease off,” he said.

The low pressure system driving the event remains positioned east of the country, pushing moisture laden winds in from the south. As those winds meet Banks Peninsula, the terrain enhances rainfall, intensifying conditions for coastal communities.

“It will slowly be getting better as the system pulls away,” Law said. “But it’s going to take its time.”

Christchurch has also experienced steady rain and strong southwesterlies, although conditions are expected to gradually improve.

“The area which is going to get the worst of the weather will be Banks Peninsula,” Law said. “That actually acts as a bit of protection for people in Christchurch.”

While a heavy rainfall watch remains in place, Law said the worst of the weather for the city should shift offshore later in the day, with winds easing into Tuesday.