Earth Hour is coming up on March 23, and taking part means everything goes off between 8:30 p.m. and 9:30 p.m.
"The intent of Earth Hour is to encourage all of us to think about how our actions are affecting the Earth," said Anne Grube of Kamloops350.org.
"The hope is that we will make a small change in our lives for one hour, which may lead to more significant changes in our lifestyles."
Participants are asked to turn off all lights and as many appliances as possible.
"It is also an opportunity to enjoy the company of family and friends, perhaps while going for an evening walk, creating some music or reading aloud together, playing a board game, or having a late supper by candlelight."
Kamloops has challenged Nanaimo to see which city will have the most residents taking part.