You can’t use cannabis at parks, on streets or sidewalks, on grade school grounds or while in a car. The law also says that you can’t use marijuana “knowingly in close physical proximity to anyone under 21 years of age” but doesn’t define “proximity.” Colleges and universities can still prohibit students from using cannabis. Landlords can ban smoking, and using marijuana is banned in all federally subsidized housing. Immigrants should also be careful: The sale and possession of marijuana could trigger deportation for non-U.S. citizens because the substance is still illegal federally.

Here's where you can use weed: in your home, if you’re the homeowner or if the owner of the home explicitly allows it. Using cannabis in your backyard or on your back porch could technically get you a citation, but the Chicago Police Department has said they don't plan to bust people for that.