Ontario electricity time-of-use rate periods will transition from winter to summer hours starting Friday, May 1, 2026, and the change will affect electricity bills for residents across Durham Region and the rest of the province through October 31.
The Ontario Energy Board sets electricity rates that govern time-of-use pricing for the majority of consumers across the province. Rates are divided into three price buckets: on-peak, mid-peak, and off-peak, with the most expensive times to use electricity shifting between the winter and summer seasons to reflect changes in overall demand patterns across the provincial power grid.
Under the summer time-of-use schedule effective May 1, on-peak hours run from 11 a.m. to 5 p.m. on weekdays, when air conditioning demand and overall electricity usage tend to be at their highest across Ontario. Mid-peak hours are from 7 a.m. to 11 a.m. and again from 5 p.m. to 7 p.m. on weekdays. Off-peak hours, which offer the cheapest electricity rates, run from 7 p.m. to 7 a.m. on weekdays and all day long on weekends and statutory holidays.
This represents a notable shift from the winter schedule, where on-peak hours typically occur during the morning and evening rush when people are getting ready for their day and returning home from work. In the summer, the peak demand shifts to the middle of the day when temperatures are highest and air conditioning systems are working their hardest across residential, commercial, and industrial buildings throughout the province.
Electricity rates themselves remain the same regardless of the season — it is only the timing of when those rates apply that changes. The time-of-use pricing structure is designed to encourage consumers to shift their electricity usage to off-peak periods when possible, helping to reduce strain on the provincial power grid during times of highest demand and supporting overall system reliability for everyone.
Durham Region residents looking to save on their electricity bills this summer should consider running major appliances like dishwashers, washing machines, and clothes dryers during off-peak hours after 7 p.m. or on weekends when rates are lowest. Using a programmable thermostat to pre-cool the home before on-peak hours begin at 11 a.m. can also help lower monthly electricity costs during the warmer months ahead.
For customers on the ultra-low overnight price plan, rates are even cheaper between midnight and 6 a.m., making overnight the most cost-effective time to charge electric vehicles, run pool pumps, or complete other energy-intensive household tasks. This plan is particularly popular with EV owners across Durham Region who prefer to charge their vehicles overnight while they sleep.
Regardless of the time of year, weekends and statutory holidays always offer off-peak rates all day long, providing consistent opportunities for savings on laundry, cooking, and other household electricity use throughout the entire summer season.
The summer time-of-use pricing period runs from May 1 through October 31, after which rates will automatically transition back to the winter schedule effective November 1, 2026. Residents can check their specific rate plans and monitor their daily usage through their local utility provider’s website or the Ontario Energy Board’s online resources at oeb.ca.
