Powerco is asking people in Whanganui and Taranaki to prepare for strong winds by securing objects that could blow into overhead power lines.
Field crews are on standby ready to respond should severe wind gusts and heavy rain arrive overnight as forecast.
Powerco Network Operations Manager Phil Marsh said trampolines, outdoor furniture and other heavy items should be securely fixed to the ground.
"Wind-blown trampolines have caused multiple power cuts in previous storms."
Other steps householders can take to prepare for possible power cuts include stocking up on torches and batteries and having a battery-powered radio.
"Make sure you have plenty of water and food supplies, and listen to the radio for up-to-date information."
He said people should call Powerco on 0800 272727 for emergencies such as trees in power lines or lines down.
"Downed lines must be treated as live at all times and people should keep clear of them."
Customers wanting information about power cuts can go to www.powerco.co.nz or call their electricity retailer.