These are the states requiring people to wear masks when out in public

Updated 2120 GMT (0520 HKT) August 17, 2020

(CNN)More states have mandated the use of masks and face coverings while in public.

After some states lifted some coronavirus restrictions, an uptick in cases has led to new restrictions in many states. The number of cases is rising in more than half of them.
That's where masks come in. A recent study found that the use of masks and face coverings has been the most effective way to reduce person-to-person spread of coronavirus.
Here are the states that require the use of masks or face coverings in public settings.

Alabama

As of July 15:
Gov. Kay Ivey issued an amended Safer at Home order which requires residents to wear a mask or face covering when in public and in close contact with other people. The order was extended through August 31, and it was expanded to include students in second grade and above.

Arkansas

As of July 20:
Gov. Asa Hutchinson announced that beginning on Monday, July 20, residents 10 years and older must wear masks when in the presence of non-household members and aren't able to socially distance. The order is enforceable and offenders can be cited for a misdemeanor or fined.

California

As of June 18:
Gov. Gavin Newsom issued a statewide order requiring the use of face coverings in public indoor spaces, including while shopping, riding on public transportation or seeking medical care.
Newsom's order also mandated the use of masks or face coverings in public outdoor spaces when social distancing is not an option. There was no guidance on how the order will be enforced or if violators will face any penalties or citations.

Colorado

As of July 17:
Gov. Jared Polis announced that residents will be required to wear masks when in public indoor spaces and not able to socially distance from others.

Connecticut

As of April 20:
Connecticut's mask requirement applies to any resident over the age of 2 in a public space where social distancing isn't possible. The rules also apply to individuals using public transportation, taxis or rideshare services.
The state's Department of Economic and Community Development also released mask guidelines for essential workers:
Employees at essential businesses must wear masks or any other material covering their mouth and nose at all times while at work. Employers must provide masks or the materials to make them. All customers under age 2 must wear them, too.
On August 14, Lieutenant Gov. Susan Bysiewicz signed an executive order that requires residents to provide a doctor's note that shows they are exempt from wearing a mask due to a medical condition.

Delaware

As of April 28:
Gov. John Carney ordered residents to wear face masks while in public, including at grocery and convenience stores, pharmacies, doctor's offices and on public transportation.
Children under the age of 12 are not required to wear face coverings, and those age 2 and under must not wear face masks due to the risk of suffocation.

District of Columbia

As of May 16:
Mayor Muriel Bowser ordered the use of masks or face coverings when conducting essential business or travel and social distancing isn't possible.
Masks or other face coverings are required in grocery stores, pharmacies and takeout restaurants. On public transportation, face coverings are required if individuals are unable to be six feet apart.
Children between the ages of 2 and 9 are advised to wear masks.

Hawaii

As of April 20:
Both customers and employees at essential businesses are required to wear cloth face coverings. Establishments must limit the number of customers allowed in and keep them six feet apart.
Anyone who violates those rules could face a fine of up to $5,000, or up to a year in prison if found guilty, according to Hawaii Gov. David Ige's order.

Illinois

As of May 1:
Gov. J.B. Pritzker ordered the use of face masks for anyone stepping outside their house.
Face coverings are required while shopping at essential businesses, traveling on public transportation, picking up food, or visiting the doctor and it's impossible to stay six feet apart.

Indiana

As of July 27:
Gov. Eric Holcomb announced that a statewide mask mandate will go into effect on July 27 due to the increase in the state's positivity rate and some counties seeing increases in cases.
The mask mandate applies to anyone who is 8 years and older, and is required in indoor public spaces, commercial entities, while using transportation services and outdoors where social distancing isn't possible.
The mask mandate will remain in effect indefinitely.

Kansas

As of July 3:
An executive order was issued by Gov. Laura Kelly mandating face masks must be worn statewide in public spaces.
Kelly, commenting on Facebook Monday, wrote, "Starting July 3, I will issue an Executive Order requiring marks be worn in indoor public spaces, and at any outdoor gathering in which social distancing cannot be maintained. This step will keep Kansans healthy, and keep Kansas open for business."

Kentucky

As of May 11: