Is Weed Smell Probable Cause To Be Searched By Police?

Cannabis is notorious for its unique and pungent aroma, making it instantly recognizable by scent alone. For years, the odor of cannabis was considered probable cause of a crime, giving police officers the authority to search individuals and automobiles for additional evidence. 

Times have changed, however, and the smell of cannabis is no longer always a valid reason for law enforcement officers to conduct a search in many states.

Is Weed Smell Probable Cause for the Police to Search?

The answer depends on your state and the setting (vehicle vs. person). In prohibition states, courts often treat cannabis odor as probable cause, particularly for vehicle searches.

In legal states, many courts say odor by itself is not enough. Even then, it can still be a factor when combined with other evidence (e.g., signs of impairment, open-container violations, under-21 possession). Always check your state’s current law.

Here are a couple of state laws that address the question:

California

In California, the most populous state with legal cannabis and an early adopter of cannabis policy reform, an appeals court ruled in 2021 that police could not use the smell of cannabis alone to search a vehicle because they could not determine if cannabis had been consumed in the vehicle.

After legalization, California courts generally find that odor alone is not enough to search a vehicle unless there are other facts suggesting a crime (e.g., signs of impairment, evidence of open-container violations, or under-21 possession). Courts have suppressed searches based largely on odor without more, but upheld them when odor was paired with factors like under-21 occupants and admissions.

New York

When New York legalized cannabis in 2021, the legislation specifically included protections against warrantless searches. Under the law, “No finding or determination of reasonable cause to believe a crime has been committed can be based solely on or in combination with the odor of cannabis or burnt cannabis,” according to a state fact sheet.

Michigan

In 2025, the Michigan Supreme Court ruled that police officers may not search motor vehicles based solely on the odor of marijuana emanating from the car, according to an article from the National Organization for the Reform of Marijuana Laws (NORML).

Virginia

Under Virginia law, no law enforcement officer “may lawfully stop, search, or seize any person, place, or thing, and no search warrant may be issued solely on the basis of the odor of marijuana.”

Illinois

Illinois is an outlier among the states that have legalized recreational cannabis. In 2024, the state Supreme Court ruled that police can search a car without a warrant based solely on the “odor of raw cannabis” emanating from the vehicle. Months earlier, however, the same court had just ruled the opposite, noting police may not search a vehicle based only on the odor of burnt cannabis coming from the vehicle, according to a report from NORML.

It should be noted that these restrictions on warrantless searches generally only apply if a search is based solely on the odor of cannabis. In other situations, the smell of cannabis in conjunction with other factors, such as evidence of impaired driving, may constitute legal probable cause for a search.

Can the Cops Pull You Over for the Smell of Weed?

Practically, it’s uncommon for an officer to detect odor from a moving car at a distance. If it does happen, however, the same restrictions on searches based solely on cannabis odor would apply. 

Whether odor can justify a stop or search depends on state law. Virginia expressly forbids stops based solely on odor. In other states, odor may contribute to reasonable suspicion or probable cause when combined with other indicators (e.g., impaired driving).

For more information, check your state's rules and regulations.

How to Protect Yourself

Even in states that allow searches based solely on the aroma of cannabis, there are steps people can take to protect themselves. Don’t hotbox the car. Doing so can permeate the vehicle’s upholstery with the pungent smell of weed smoke and arouse a suspicious police officer’s attention.

If you need to take your cannabis on-the-go, you'll need to properly secure it. It is also important not to leave cannabis in view of someone outside the vehicle. Instead, keep weed out of sight in a nondescript container. If your car has a trunk, keeping your stash locked inside is the best way to transport weed. 

Note that some legal states have laws against carrying an open container of cannabis in an automobile. When visiting dispensaries in these jurisdictions, it’s best to wait until you get home or reach your destination before opening your purchase. Be sure to check the state regulations for more information.

You can also protect yourself by avoiding behavior that will draw the attention of law enforcement, such as openly smoking weed in a vehicle. Don’t drive while high. Being under the influence while behind the wheel is a sure way to get a DUI.

Are There Protections for Cannabis Patients?

Registered patients may be able to avoid a search if they show their state-issued medical cannabis identification card or otherwise share their status during an encounter with law enforcement. 

In 2019, a Pennsylvania judge ruled that police did not have a valid reason to search a car based on the odor of cannabis after a passenger in the vehicle revealed they had a medical cannabis card, according to a report from PBS.

Every state is different, so it's always best to familiarize yourself with your state's laws. Securing your cannabis in the trunk of the vehicle is always a good way to mitigate suspicion of driving intoxicated.

What Can Patients Do to Advocate for Their Rights?

While cannabis policy reform has come a long way, there is still work to do to ensure everybody has the right to use the plant medicinally, without the fear of police interference. If searches based solely on the smell of weed are still allowed in your state, consider becoming an advocate for further reform.

To learn more about cannabis policy reform advocacy, becoming a member of one or more of the many local, state, and national organizations can be a great way to start. The groups Americans for Safe Access, the National Organization for the Reform of Marijuana Laws, the Marijuana Policy Project, and the American Civil Liberties Union all work to protect the rights of cannabis patients and consumers. Members and supporters can back these groups through letter-writing campaigns, demonstrations, community outreach, and other activities.

With continued advocacy, the era of police conducting searches based solely on the odor of cannabis will fade into history.

The information in this article and any included images or charts are for educational purposes only. This information is neither a substitute for, nor does it replace, professional legal advice or medical advice, diagnosis, or treatment. If you have any concerns or questions about laws, regulations, or your health, you should always consult with an attorney, physician or other licensed professional.