Yesterday's weather caused chaos in the upper North Island yesterday - and MetService says it can expect further downpours today.

Slips and flash flooding hit several regions yesterday, with northwestern Bay of Plenty receiving 53 millimetres of rain in just one hour.

Peek downfall in Northland saw 24.5 millimetres fall in one hour, while Auckland's wettest hour saw 26.5 millimetres fall.

MetService lead forecaster Michael Martens says a front is making its way down the island, and more thunderstorms are expected.

Emergency services received hundreds of calls yesterday, including 40 alone in the Bay of Plenty.

Around 20 homes in Auckland also received water damage.