The rate hike applies to most households and small businesses, and is the latest in a series of increases that have made the cost of hydro a contentious issue for many Ontarians.
Data from the provincial regulator show a steady increase in hydro rates since 2008, when they dipped slightly.
The cost of electricity during on-peak hours has jumped 77 per cent since Smart Meters became common five years ago. In November 2010, the price was 9.9 cents/kWh.
Ontario Hydro charges on-peak rates in the morning and early evening in the winter, and during the afternoon in the summer. Off-peak rates apply year-round from 7 p.m. to 7 a.m., and all day on weekends and holidays.