Indiana has another next-door neighbor that allows recreational marijuana use.

Illinois Gov. JB Pritzker signed a bill June 25 that legalizes the recreational use of marijuana. It also expunges the criminal records of people with minor pot possession convictions in the state.

With Pritzker's signature, Illinois follows in the footsteps of Michigan, where the legal recreational use of marijuana began in December 2018 after voters OK'd a ballot measure. Neither Kentucky nor Indiana allow marijuana use within their borders.

Here's what we know about Illinois' recreational marijuana law, and what it means for Hoosiers.

When will marijuana be legal in Illinois?

The bill to legalize recreational marijuana in Illinois goes into effect Jan. 1, 2020. At that point, adult consumers aged 21 or older would then be able to buy marijuana for recreational use from licensed sellers.

How much weed would be allowed in Illinois?

Under the law, adults may buy and possess up to 30 grams of raw cannabis and 5 grams of cannabis products in concentrated form, according to the Marijuana Policy Project, which worked with Illinois lawmakers to write the legislation.

Also legal to buy would be cannabis-infused products, such as edibles or tinctures, that contain no more than 500 milligrams of THC, the chemical that makes users high.

Visitors to Illinois could buy half of those amounts.

Will there be marijuana dispensaries in Illinois?

Yes. Licensed dispensaries will be the only place where you can legally buy recreational marijuana if the law goes into effect.

Illinois, which began selling medical marijuana in 2015, now has 55 such dispensaries. Those dispensaries can apply to sell pot for recreational use, too, and the new law also allows them to open a second location for that purpose.

According to The Chicago Tribune, some dispensaries are already planning building expansions, staffing increases and new technology to handle the recreational marijuana customers as well as an expected increase in medical marijuana sales.

Ohio's law:Medical marijuana is now legal in Ohio. Here's what it means for Indiana.

Where is recreational weed legal?

There are now 11 states that allow the recreational use of marijuana: Alaska, California, Colorado, Illinois, Maine, Massachusetts, Michigan, Oregon, Nevada, Vermont and Washington, along with the District of Columbia.

More than 30 states, including Illinois and Ohio, allow the use of medical marijuana.

Where could you legally use recreational weed in Illinois?

Under the new law, people will be able to smoke or consume edibles in one’s own home, as well as in certain cannabis-related businesses.

However, marijuana use will still be prohibited in these places:

Any public place, including streets or parks.

In motor vehicles.

Near someone under 21.

On school grounds, except for medical marijuana users.

Its use also could be prohibited on private property.

Beware:CBD flower is legal in Indiana. But it still could get you arrested. Here's why.

What is Indiana's stance on marijuana?

It is illegal to possess marijuana in any form in Indiana. Possession of less than 30 grams is a misdemeanor offense, and more than 30 grams is a felony.

In March of 2018, Gov. Eric Holcomb signed a measure legalizing low-THC cannabidiol oil, known as CBD oil, in Indiana. This year, Holcomb signed into law another measure which sets up a regulatory structure for hemp, including an advisory committee that will report back to state officials for a period of about two years.

However, efforts to legalize marijuana for any use have failed in the Indiana General Assembly in recent years.

Cannabinoid product:What we know about CBD oil and how it can be legally used in Indiana

Can I bring marijuana from another state to Indiana?

Even if you purchase it legally in Illinois, Michigan or any other state that has legalized marijuana, you cannot bring it here. Buying it legally somewhere else does not make it legal to possess in Indiana.

Michigan's marijuana law:Recreational marijuana is now legal in Michigan. Here's what it means for Indiana.

Can I use marijuana in another state and drive back to Indiana?

It's not advisable. It will still be illegal to drive under the influence of cannabis in any state.

You may think you're no longer high, but even a trace amount of THC, the hallucinogenic ingredient in marijuana, may show up in a blood test for up to a few weeks after use.

If an officer in Indiana suspects you may be driving while impaired, even if with a substance other than alcohol, they can request a blood test. If you refuse, you could be held "for a reasonable amount of time" until the investigating officer can get a search warrant to obtain that blood sample, according to Capt. David Bursten of the Indiana State Police.

Hemp in Indiana:Bill legalizing hemp growth and sales in Indiana clears final hurdle, heads to governor

What does the federal government say about marijuana?

Despite what a state may allow, it's still illegal to possess marijuana, even for medical use, under the federal Controlled Substances Act passed in 1970.

Reporters Kellie Hwang and Andrew Clark of IndyStar and Trevor Hughes of USA TODAY contributed to this story.

Call IndyStar digital producer Dwight Adams at 317-444-6532. Follow him on Twitter: @hdwightadams.