Yes and no. In California, it is not illegal to have weed in the car if you are 21 or older, the amount stays within the legal limit, the cannabis is sealed or in the trunk, and no one is smoking, vaping, or eating it while the vehicle is in motion. Break any of those conditions and you are looking at anything from a $100 infraction to a DUI that carries jail time and a suspended license.
How Much You Can Have
Under Health and Safety Code 11362.1, an adult 21 or older can possess up to 28.5 grams (about one ounce) of cannabis flower or up to eight grams of concentrated cannabis, including the concentrate inside edibles or vape cartridges.1California Legislative Information. California Health and Safety Code 11362.1 Those limits apply whether the cannabis is on you or somewhere in the car. A dispensary receipt does not raise the ceiling.
Medical patients with a valid physician’s recommendation can carry more. Qualifying patients may possess up to eight ounces of dried cannabis, and a physician can authorize larger amounts when medically necessary.2California Department of Public Health. Cannabis Health Information Initiative FAQs Medical patients still have to follow the same open container and storage rules in the car.
Going over the recreational limit without a medical recommendation can bring charges under Health and Safety Code 11357, or 11359 if officers suspect intent to sell based on quantity, packaging, or how the cannabis is divided. Possession for sale is a misdemeanor for anyone 18 or older, carrying up to six months in county jail and a fine of up to $500, with felony elevation possible where aggravating factors like prior drug convictions are present.
How It Has to Be Stored
Vehicle Code 23222(b) makes it an infraction for a driver to have an open container of cannabis while operating a vehicle on a highway or certain other public lands.3California Legislative Information. California Vehicle Code 23222 “Open” means any receptacle that has been opened, has a broken seal, or loose flower not in a container at all. The fine runs up to $100.
The statute does not require the original dispensary packaging. Any sealed container is fine so long as it hasn’t been opened. Once the seal is broken, though, you cannot fix the problem by taping it back up or transferring the contents into a zip-lock bag. The plain language treats anything that has been opened as an open container. The safest move at that point is the trunk, which falls outside the reach of the rule.
Product type matters here. A vape cartridge that has been used is an opened receptacle. Edibles pulled from their original sealed packaging and dropped into a purse are loose product without a sealed container. Tinctures with a broken dropper seal are in the same bucket. Any of these belong in the trunk once opened.
One wrinkle: the $100 open-container fine under 23222(b) targets the driver specifically. Its language covers “a person who has in their possession on their person, while driving a motor vehicle.” Passengers are separately barred from smoking or ingesting cannabis in a vehicle by Health and Safety Code 11362.3(a)(8), but the Vehicle Code open-container penalty falls on the driver.4California Department of Industrial Relations. Health and Safety Code 11362.3
Rideshares and Taxis
The same rules follow you into an Uber or Lyft, and the platforms add their own layer. Uber’s community guidelines prohibit bringing open containers of drugs or alcohol into a vehicle, and drug use during a ride is not allowed.5Uber. Following the Law A driver can end the trip and report you. Keep your cannabis sealed regardless of whose car you’re in.
No Smoking, Vaping, or Eating in the Car
Health and Safety Code 11362.3 prohibits both drivers and passengers from smoking or ingesting cannabis in a moving vehicle.4California Department of Industrial Relations. Health and Safety Code 11362.3 Being a passenger does not create an exception. Pulling out an edible in the back seat or hitting a vape in the passenger seat violates the same rule that keeps the driver from doing it.
Cannabis DUI
Driving under the influence of cannabis is illegal under Vehicle Code 23152(f), and California treats it as seriously as an alcohol DUI.6California Legislative Information. California Vehicle Code 23152 There is no equivalent of the 0.08% blood alcohol threshold. California has not set a per se nanogram limit for THC, so prosecutors have to prove actual impairment rather than point to a number.
Proving impairment is not especially hard for the state. Officers trained as Drug Recognition Experts evaluate physical signs like bloodshot eyes, slow reaction time, and coordination problems. A driver suspected of being high will typically be asked to perform field sobriety tests and may be asked to submit to a blood test. THC does linger in the body far longer than alcohol, so someone who used the previous day can still test positive without being impaired. That gives defense attorneys something to work with, but it does not prevent an arrest.
A first-offense cannabis DUI carries 96 hours to six months in county jail, fines from $390 to $1,000 before court assessments, a four-month license suspension, and a mandatory DUI education program. Second and third offenses within ten years raise every one of those penalties.
Chemical Testing and Refusal
Under Vehicle Code 23612, anyone lawfully arrested for DUI in California has already given implied consent to chemical testing by the act of driving on state roads.7California Legislative Information. California Vehicle Code 23612 Refusing a blood test after a lawful arrest triggers an automatic one-year license suspension for a first refusal, and the refusal can be used as evidence in the DUI case. Roadside saliva screening tests are different. Those are not covered by implied consent, so you can decline them, though officers may note the refusal.
Can Police Search Your Car Over the Smell of Cannabis?
The answer shifted after legalization. Because adults can legally possess cannabis, the smell of cannabis alone generally does not give police probable cause to search your vehicle. Possession is no longer a crime for someone 21 or older within the legal limits, so the odor does not automatically point to criminal activity the way it did before Prop 64.
There are exceptions. If you are under 21, the smell of burnt cannabis suggests illegal use and can contribute to probable cause. If an officer smells cannabis and also sees signs of impairment, that combination can justify a DUI investigation and potentially a search. And where the officer has other reasons to suspect a crime, the odor becomes one factor in a totality-of-the-circumstances analysis. For a sober adult 21 or older driving with a legal amount of properly stored cannabis, the smell by itself should not trigger a vehicle search.
Drivers and Passengers Under 21
Cannabis possession is completely illegal for anyone under 21, regardless of storage. For people aged 18 to 20, possessing any amount is an infraction under Health and Safety Code 11357. For those under 18, a first offense is also an infraction but requires drug education or counseling and community service rather than a fine. The rules apply whether the cannabis is on the person or in the car.
The practical impact goes further. A driver under 21 caught with any amount, even a sealed container, faces a situation where the odor of cannabis can give officers grounds for further investigation, because possession itself is illegal at that age. A DUI arrest for someone under 21 also triggers a one-year license suspension rather than the four-month suspension that applies to adults.
Children in the Vehicle
A child in the car raises the stakes sharply. Smoking or eating cannabis with anyone under 21 present as a passenger is specifically prohibited.4California Department of Industrial Relations. Health and Safety Code 11362.3 Beyond that, if law enforcement believes the situation puts a child at risk, Penal Code 273a allows a child endangerment charge. As a misdemeanor, that carries up to one year in county jail. As a felony, where the circumstances are likely to produce great bodily harm or death, the sentence jumps to two, four, or six years in state prison.8California Legislative Information. California Penal Code 273a
A cannabis DUI with a child under 14 in the vehicle triggers mandatory sentencing enhancements under Vehicle Code 23572. These are added on top of the DUI penalties:9California Legislative Information. California Vehicle Code 23572
- First DUI offense: 48 additional hours in county jail
- Second DUI offense: 10 additional days in county jail
- Third DUI offense: 30 additional days in county jail
- Fourth or subsequent DUI: 90 additional days in county jail
Child Protective Services can also open an investigation if authorities determine a child’s welfare is at risk, which brings a separate set of consequences unrelated to the criminal case.
Places You Cannot Take It, Even Sealed
Some locations create additional exposure even when you are following every other rule.
California law separates the grounds of a school from the area around them. Possessing cannabis on the grounds of a school, daycare center, or youth center while children are present is a separate violation under Health and Safety Code 11362.3(a)(5). Smoking has a wider buffer: it is prohibited within 1,000 feet of a school, daycare, or youth center while children are present under 11362.3(a)(4). Driving past a school with sealed cannabis in the trunk does not violate either provision. Pulling into a school parking lot with cannabis in the car, or smoking in a car within several blocks of a school, does.
Federal land is a different category. Cannabis remains illegal under federal law, and federal property is governed by federal rules regardless of what California allows. Driving through a national park, onto a military base, or near a federal courthouse with cannabis in the vehicle exposes you to federal simple possession charges under 21 U.S.C. 844.10Office of the Law Revision Counsel. 21 USC 844 – Penalties for Simple Possession Federal rangers in Yosemite, Joshua Tree, or Death Valley enforce federal law, and a California dispensary receipt will not help. Federal border checkpoints operated by U.S. Customs and Border Protection within California also enforce federal law, and bringing cannabis to any border crossing can result in seizure and civil penalties of up to $1,000.11U.S. Customs and Border Protection. CBP Reminds Public That All Marijuana Imports Are Prohibited
Crossing state lines is a federal trafficking offense even if both states have legalized cannabis. Driving from California to Nevada or Oregon with cannabis in the car means transporting a federally controlled substance across a state border. Federal prosecution of small personal amounts is unlikely, but the legal exposure is real, with penalties up to five years in federal prison for less than 50 kilograms.12DEA. Federal Trafficking Penalties The safe approach is to consume or leave behind any cannabis before crossing a state line.
Commercial Drivers
Commercial driver’s license holders operate under a different standard. Federal Department of Transportation rules apply to anyone in a safety-sensitive transportation role, and those rules treat cannabis the same way they did before any state legalized it. The DOT tests for THC as one of five controlled substances in mandatory drug screening, and a verified positive test result requires immediate removal from safety-sensitive duties and evaluation by a Substance Abuse Professional.13Federal Motor Carrier Safety Administration. Implementation Guidelines for Alcohol and Drug Regulations
A DUI involving any controlled substance, including cannabis, brings a minimum one-year CDL disqualification. If the commercial vehicle was being used to manufacture or distribute a controlled substance, the disqualification becomes a lifetime ban.14The Motor Carrier Safety Planner. Disqualification of Drivers 383.51 These consequences apply even if the CDL holder was driving a personal vehicle at the time of the offense.