A lot of people across Ontario heeded the Earth Hour call and turned off lights between 8:30 and 9:30 p.m. on Saturday night.
The global event was launched in Australia in 2007 to draw attention to environmental issues including climate change.
In Toronto, the city saw an electricity dip of 3.2 per cent, roughly the equivalent of 36,000 homes of the grid, says Toronto Hydro. That's down from 3.5 per cent, or roughly 42,000 homes, during last year's Earth Hour.
Still, the power company was enthusiastic.
"While participation in Earth Hour does seem to be declining, our customers are conserving electricity as part of their everyday lives," spokeswoman Tori Gass said.
Annual power use in Toronto has dropped by more than 23 per cent since 2005, Gass said.
Some Torontonians gathered by lantern light awaiting the countdown to Earth Hour.
City Hall and the CN Tower were among the buildings that went dark for the event.
PowerStream, which serves nine municipalities north of Toronto, reported a 4.3 per cent drop in electricity consumption during Earth Hour, down slightly from the six per cent reduction achieved last year.