Most U.S. middle and high schools start too early — with an average start time of around 8:00 a.m., according to a new study. Some children's health organizations recommend that schools start no earlier than 8:30 a.m., to help teens get the sleep they need.

The study also found that school starts times varied greatly by state, with schools in Louisiana starting at 7:40 a.m., on average, and schools in Alaska starting at 8:33 a.m., on average.

The average start time for middle and high schools in each state is listed below. (In one state, Maryland, there was not enough information to determine the average start time.)

Alabama: 7:49 a.m.

Alaska: 8:33 a.m.

Arizona: 8:03 a.m.

Arkansas: 8:01 a.m.

California: 8:07 a.m.

Colorado: 7:54 a.m.

Connecticut: 7:46 a.m.

Delaware: 7:42 a.m.

Florida: 8:17 am

Georgia : 8:09 a.m.

Hawaii: 8:03 a.m.

Idaho: 8:13 a.m.

Illinois: 8:13 a.m.

Indiana: 7:58 a.m.

Iowa: 8:23 a.m.

Kansas: 8:00 a.m.

Kentucky: 8:03 a.m.

Louisiana: 7:40 a.m.

Maine: 7:53 a.m.

Maryland: N/A

Massachusetts: 7:53 a.m.

Michigan: 7:54 a.m.

Minnesota: 8:18 a.m.

Mississippi: 7:47 a.m.

Missouri: 7:54 a.m.

Montana: 8:13 a.m.

Nebraska: 8:07 a.m.

Nevada: 7:51 a.m.

New Hampshire: 7:46 a.m.

New Jersey: 8:00 a.m.

New Mexico: 8:10 a.m.

New York: 7:59 a.m.

North Carolina: 8:03 a.m.

North Dakota: 8:31 a.m.

Ohio: 7:52 a.m.

Oklahoma: 8:10 a.m.

Oregon: 8:14 a.m.

Pennsylvania: 7:48 a.m.

Rhode Island: 7:50 a.m.

South Carolina: 8:03 a.m.

South Dakota: 8:13 a.m.

Tennessee: 7:57 a.m.

Texas: 8:05 a.m.

Utah: 8:05 a.m.

Vermont: 8:05 a.m.

Virginia: 8:04 a.m.

Washington: 8:08 a.m.

West Virginia: 7:54 a.m.

Wisconsin: 7:59 a.m.

Wyoming: 7:59 a.m.

Follow Rachael Rettner @RachaelRettner. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.