Areas in the north left reeling from heavy rain are being warned it's not over yet.

The area has been drenched by rain for several days and nights, causing flooding in homes, and slips onto properties across southern Auckland and the Coromandel.

This morning at least three early childhood centres and one primary school are still closed because of flooding, and roads across the region are still affected.

MetService meteorologist Rabi Kandula says it's going to be the same story again on the Peninsula today.

"The east coast of the Coromandel Peninsula, we're expecting that it's just going to get significant rainfall amounts right through the next 24 hours."

NIWA Meteorologist Ben Noll warned drivers to be vigilant on the roads.

"Out on the roads on Friday night do watch for flooding if you do have plans - slips as well," he said.

"Those waking up on Saturday morning across the upper North Island could be waking up to some serious conditions where the most rain does fall."

The Waikato Regional Council is ready and willing to assist in the Coromandel area if more heavy rain continues over the next three days.

The forecast is prompting the Waikato Civil Defence group emergency management office to be activated in support mode.

The Waikato regional hazards team also set up a flood operation room in Hamilton on Wednesday to monitor developments, which can easily be re-activated if required.

Council spokesperson Stephen Ward says they have local flood response rooms being activated in Whitianga and Paeroa, in case they're needed.

The area's Civil Defence controller Garry Towler said there's big clean-up ahead, and land slips will take the most time to deal with.

"There's some major, major slips on both our reserve land and private property... I would say it's the best part of maybe four weeks before we can put a tick in the box that this event has been dealt to."