In Minnesota, you can be charged with DWI if you drive while under the influence of cannabis. Unlike other Schedule I and II drugs, there is no ‘any amount’ rule for THC, so the state must prove impairment, not just a positive test. Penalties and license revocation follow the same DWI degrees as alcohol cases.
Think You’re Safe to Drive After Smoking Weed? Think Again. Marijuana DWI Laws in Minnesota are no joke.
Minnesota has embraced legalized marijuana, but that doesn’t mean you have a free pass to drive after consuming cannabis. While most people associate DWIs with alcohol, the reality is that Minnesota’s DWI laws apply to any substance that impairs your ability to drive, including marijuana.
And here’s where it gets tricky: You don’t even have to be high at the time of the traffic stop to be charged with a marijuana DWI.
That’s right. Unlike alcohol, where there’s a clear limit of 0.08% BAC, there’s no established THC limit in Minnesota. Officers and prosecutors rely on subjective tests and chemical results that can be misleading or outright unfair.
Before you assume you’re in the clear, let’s dive into the details.
How Does Minnesota Define a Marijuana DWI?
In Minnesota, driving while impaired (DWI) isn’t just about alcohol. Under state law, you can be charged with a marijuana-related DWI if:
- You are under the influence of marijuana while driving
- You have any amount of a Schedule I or II controlled substance in your system, but this rule does not apply to marijuana or THC (Minn. Stat. 169A.20, subd. 1(7))
What does this mean in real life?
- You don’t need to be visibly high to get charged – If a police officer believes your driving is impaired, you can be arrested even if you feel completely normal.
- A positive drug test could land you in court – Unlike alcohol, where impairment wears off quickly, THC can stay in your system for days or even weeks. A test that detects residual THC can be used as evidence, but the state still has to prove you were under the influence.
- Medical marijuana users aren’t completely safe either – While registered medical cannabis users have some protections, they can still be arrested if an officer believes they are impaired at the time of driving.
Minnesota has no numeric THC limit, which makes marijuana DWIs depend heavily on officer observations.
If you feel that you have been given an unfair marijuana DWI in Minnesota, contact our team today to discuss your options.
Why Marijuana DWIs Are So Problematic
1. THC Lingers in Your Body
Unlike alcohol, where a breathalyzer gives a clear, immediate measurement, THC doesn’t work that way. It can remain in your bloodstream for days or even weeks, especially if you’re a regular user. That means you could test positive for THC long after the effects have worn off.
This creates a problem: a test can show THC after the effects have worn off. That is why the state must prove impairment, not just a positive test.
2. Police Officers Use Unreliable Field Tests
Since there’s no breathalyzer for marijuana, law enforcement officers rely on field sobriety tests and Drug Recognition Evaluators (DREs) to determine impairment.
Here are the issues:
- Field sobriety tests are designed for alcohol, not marijuana. Standardized tests like the “walk-and-turn” or “one-leg stand” were created to measure alcohol impairment, not cannabis. Being clumsy or nervous could be mistaken for intoxication.
- Drug Recognition Evaluators are not foolproof. DRE officers undergo specialized training, but their assessments are subjective and prone to human error. Many cases have shown that their evaluations are often inaccurate.
- Blood and urine tests don’t measure actual impairment. A person who smoked marijuana a week ago could still have THC metabolites in their system, yet be completely unimpaired at the time of arrest.
3. Harsh Penalties Even for First-Time Offenders
Even if you’ve never been in trouble with the law before, a marijuana DWI can come with serious consequences, including:
- Up to a $1,000 fine
- Possible jail time (up to 90 days for a first offense)
- License revocation for at least 90 days
- Increased insurance costs
- Potential job consequences, especially if you drive for work
For repeat offenders or cases involving aggravating factors (such as a child in the car), penalties can escalate quickly to felony charges, long-term license revocation and mandatory ignition interlock devices.
How to Protect Yourself from a Marijuana DWI
Because of how flawed Minnesota’s marijuana DWI laws are, you need to be extremely careful if you use cannabis and drive. Here are some ways to protect yourself:
- Know Your Rights – If an officer pulls you over, you have the right to remain silent and decline field sobriety tests. Be polite, but firm, about wanted to speak with an attorney before submitting to any tests.
- Don’t Admit to Cannabis Use – If an officer asks if you’ve smoked recently, don’t volunteer that information. Saying “I smoked earlier today” can be used against you, even if you were completely sober at the time of the stop.
- Challenge the Evidence – Many marijuana DWI cases rely on subjective or flawed testing. A DWI defense attorney can question the accuracy of these tests and fight for your case to be dismissed.
- Consult a Lawyer Immediately – If you are arrested for a marijuana DWI, do not try to handle it on your own. An experienced defense attorney can challenge improper traffic stops, unreliable test results and weak evidence to get your charges reduced or dropped. One of our attorneys would be happy to speak with you to let you know what to do next.
Charged with a Marijuana DWI? Fight Back.
A marijuana DWI is more than just an inconvenience, it can jeopardize your freedom, your job and your future. But just because you were charged doesn’t mean you’re guilty. Many marijuana DWI cases are based on shaky evidence that can be challenged in court.
At Martine Law, we defend drivers charged with DWI. We will work to protect your rights.
Don’t let one mistake define your future. Call us today for a free consultation and take control of your defense.
This page states Minnesota law and is for general information, not legal advice.
Call (612) 979-1305 for a free consultation. Phones and chat are answered 24/7, with AI covering when no staff is free.
Frequently asked questions
Is there a legal THC limit for driving in Minnesota?
No. Minnesota has no numeric THC limit, and the ‘any amount’ drug rule does not apply to marijuana. The state has to prove you were under the influence of cannabis while driving.
Can a positive THC blood test alone lead to a DWI conviction?
A test showing THC is evidence, but because THC can remain in the body after effects wear off, the state still needs to prove impairment, usually with driving behavior, officer observations and drug recognition evaluation.
What are the penalties for a first marijuana DWI?
The same as an alcohol DWI. A first offense with no aggravating factors is a misdemeanor with up to 90 days in jail and a $1,000 fine, plus license revocation.
Is medical cannabis a defense to DWI?
No. Having a medical or legal right to use cannabis does not allow you to drive while impaired by it.
