State Highway 29 over the Kaimai Range has been closed to large vehicles because of heavy wind.
Traffic will be directed at Lower Kaimai until further notice, police said in a statement.
Metservice has issued a heavy rain warning for the Bay of Plenty.
It said periods of rain were expected west of Rotorua, easing around midday Sunday, with the heaviest falls likely Sunday morning.
In the 28 hours from 9am Saturday until 1pm Sunday, 70mm to 100mm was expected to accumulate.
Peak intensities of 15mm to 25mm per hour were expected late Sunday morning and early afternoon.