Driving in Washington state? Know these cannabis road rules
Even in a state as progressive as Washington, cannabis use may still get you in trouble.
That’s why it’s important to know the laws around cannabis before partaking — especially if you plan to travel.
McClatchy Media’s Northwest service journalism team has researched the Evergreen State’s weed road rules ahead of April 20, also known as cannabis holiday 420.
Here’s what to know:
Can you get a DUI for cannabis in Washington state?
The Washington State Department of Licensing defines driving under the influence of intoxicants as “operating a vehicle while affected by alcohol, drugs or both.”
If your blood has a THC concentration of 5.00 or higher “within two hours after driving,” you will be found guilty of DUI, the Revised Code of Washington says.
Drivers under age 21 cannot have any THC in their blood while driving, state law says.
The punishment for driving under the influence of cannabis varies based on factors including the level of impairment, if there was a collision and whether minors were in the vehicle.
You could face fines up to $5,000 and potentially get your license suspended.
Read more:
Can you get pulled over for smelling like weed?
In Washington state, the smell of weed alone is not enough to pull someone over or arrest them on suspicion of DUI, according to Trooper Daniel Mosqueda with the Washington State Patrol.
Troopers rely on a “totality of indicators” to determine if drivers are under the influence, he said.
You can be pulled over if you show “signs of impairment” such as slow speech, confusion or driving and stopping too slow, Mosqueda previously told McClatchy Media.
Read more:
Can I drive with weed in my car in Washington?
Just like alcohol, Washington law restricts how you can store open containers of cannabis in your vehicle.
You can legally keep cannabis products in the car with you as long as they’re sealed shut in their original packaging.
Once the seal’s been broken or contents partially removed, you must keep the container “in the trunk of the vehicle or in some other area of the vehicle not normally occupied by the driver or passengers,” the Revised Code of Washington says.
The glove or utility compartment doesn’t count, according to state law.
Read more:
Can I take cannabis across state lines?
Medical and recreational use of cannabis is legal Washington state.
Neighboring Idaho, however, is one of four states across the nation that have yet to decriminalize cannabis.
It’s illegal to possess, sell or distribute cannabis products in Idaho — even if you legally purchase weed in another state.
If you’re caught, you could face thousands of dollars in fines and up to 15 years in jail.
You could also be charged with federal drug trafficking crimes for crossing state lines with cannabis.
No matter your destination, it’s against federal law to take cannabis on a plane.
Read more:
Can I bring weed into Canada from Washington?
Traveling from Washington state to Canada means stopping at a Border Control checkpoint.
You’ll be required to “declare all of the goods you acquired while outside Canada, such as purchases, gifts, prizes or awards that you are bringing with you or are having shipped to you,” the Canadian government said.
You cannot bring cannabis into Canada without the proper documentation. Read more:
McClatchy Media’s Julia Hawkins and Shaun Goodwin contributed reporting used in this article.
This story was originally published April 15, 2026 at 5:00 AM with the headline "Driving in Washington state? Know these cannabis road rules."