Some homes in the central North Island could be evacuated, following a night of heavy rain in many parts of the country

Search and rescue crews are knocking on the doors of about 70 homes near the Tauranga-Taupo River, warning people to prepare for evacuation.

Emergency services are also dealing with dozens of reports of flooding, and trees falling onto house power lines, across Northland, Auckland, Waikato and Bay of Plenty.

The worst flooding is in Auckland, which was battered by thunderstorms last night.

Snow is also falling on the South Island passes, blocking State Highway 80 from Lake Pukaki to Aoraki and State Highway 8 between Lake Pukaki to Fairlie.