Metservice forecaster Allister Gorman said wind gusts greater than 110 km/hr could cause some structural damage, including trees and power lines, and may make driving hazardous. If any tornados occur, they will only affect very localised areas.
The severe weather watch stretches across the North Island, with most regions affected.
Rotorua is expected to reach a high temperature of 14C maximum, with a low of 10C overnight.
A Severe Thunderstorm Watch means conditions are favourable for severe thunderstorms in and close to the watch area. People in these areas should be on the lookout for threatening weather conditions and monitor for possible Severe Thunderstorm Warnings.