An orange heavy rain warning is in place for the Bay of Plenty, including Rotorua and west of Whakatāne.

The warning is in place for the 21 hours from 6pm today until 2pm tomorrow.

The Metservice warns to expect 100mm to 140mm of rain.

At peak times, 10mm to 20mm/h should be expected, but increasing to 25mm to 40mm/h in possible localised downpours tomorrow morning and early afternoon.

There is a possibility of thunderstorms tomorrow, but only a minimal chance the weather warning will be upgraded to red.

MetService warns streams and rivers may rise rapidly, there could also be surface flooding, slips, and difficult driving conditions.

Residents should clear drains and gutters to prepare for heavy rain and low-lying areas should be avoided. Motorists should drive with caution.