Residents and businesses in Yellowknife and Hay River will be joining people around the world tonight in turning off their lights to mark Earth Hour.
The initiative was started in Australia back in 2007 as a way to draw attention to environmental issues like climate change.
This year, Earth Hour is set to be a record-breaking celebration of our planet with an unprecedented 172 countries and territories across 24 time zones having confirmed their participation.
The event has also been embraced by Canadian utilities, with many devoting space on their websites to the annual event.
The main organizer, the World Wildlife Fund, is asking people to turn off their lights for one hour starting at 8:30pm local time.
In Yellowknife, hundreds of residents will be spending that time around a fire.
Watch: Earth Hour 2015 Official Video