A severe thunderstorm watch has been issued for the Bay of Plenty with temperatures expected to reach 28 degree later today.

An overnight low of 20 degrees is being prediction for tonight.

Thunderstorms are likely for parts of the Bay of Plenty. Image: MetService.

The MetService says thunderstorms are expected to develop over parts of the North Island again during Saturday afternoon and evening.

'About inland areas of Gisborne and Hawke's Bay and eastern areas of Bay of Plenty, Taupo and Taihape, some of these thunderstorms could become severe during Saturday afternoon and early evening, leading to localised downpours with rainfall intensities reaching 25 to 40mm per hour. There may also be some hail as well,” says a statement from the weather organisation.

'Rainfall of this intensity can cause flash flooding, especially about low-lying areas such as streams, rivers or narrow valleys, and may also lead to slips. Driving conditions will also be hazardous with surface flooding and poor visibility in heavy rain.”