Alabama
Headlights are required to be on when wipers are in use or visibility is less than 500 feet, as well as 30 minutes after sunset and 30 minutes before sunrise.
Headlight Use
Alaska
Headlights are required to be on when speed exceeds 45 mph on designated highways or when visibility is less than 1000 feet.
Arkansas
Headlights are required 1/2 hour after sunset to 1/2 hour before sunrise, when wipers are in use, or when visibility is less than 500 feet.
California
Headlights are required to be on during darkness, when wipers are in continuous use, or when visibility is less than 1000 feet.
Colorado
Headlights are required to be on between sunset and sunrise, and when visibility is less than 1000 feet.
Connecticut
Headlights are required to be on 1/2 hour after sunset to 1/2 hour before sunrise, in conditions of insufficient light/adverse weather, or when visibility is less than 500 feet.
Delaware
Headlights are required to be on from sunset to sunrise, during precipitation, when wipers are in use, or when visibility is less than 1000 feet.
District of Columbia
Headlights are required to be on when visibility is less than 500 feet. Headlights must be used one-half hour after sunset to one-half hour before sunrise. Headlights must be used when windshield wipers are in use and also in tunnels.
Florida
Headlights are required to be on from sunset to sunrise, in conditions of insufficient light/adverse weather (rain, smoke, fog).
Georgia
Headlights are required to be on 1/2 hour after sunset to 1/2 hour before sunrise, when visibility is less than 500 feet, and in conditions of insufficient light/adverse weather.
Idaho
Headlights are required to be on from sunset to sunrise and when visibility is less than 500 feet.
Illinois
Headlights are required to be on from sunset to sunrise, when wipers are in use, or when visibility is less than 1000 feet.
Indiana
Headlights are required to be on from sunset to sunrise and when visibility is less than 500 feet. Headlights must be white or amber.
Iowa
Headlights must be on from sunset to sunrise, when visibility is less than 500 feet, or in conditions of insufficient light/adverse weather.
Kansas
Headlights are required to be on from sunset to sunrise, due to insufficient light or unfavorable atmospheric conditions, including smoke or fog, if visibility is less than 1000 feet, or when windshield wipers are in continuous use as a result of rain, sleet, or snow.
Louisiana
Headlights are required to be on from sunset to sunrise, when wipers are in use, or when conditions of insufficient light or unfavorable atmospheric conditions limit visibility to 500 feet.
Maine
Headlights are required to be on 1/2 hour after sunset to 1/2 hour before sunrise, when wipers are in use, when visibility is less than 1000 feet, or in conditions of insufficient light/adverse weather.
Massachusetts
Headlights are required to be on one half an hour after sunset to one half an hour before sunrise, and during any other period when visibility is reduced to 500 feet by atmospheric conditions, such as rain, snow, fog, or when wipers are in use.
Michigan
Headlights are required to be on 1/2 hour after sunset to 1/2 hour before sunrise, and when visibility is less than 500 feet.
Minnesota
Headlights must be on from sunset to sunrise, in rain, slow, sleet, or hail, or when conditions of insufficient light/adverse weather limit visibility to 500 feet.
Mississippi
Headlights are required to be on from sunset to sunrise, and when visibility is less than 500 feet.
Missouri
Headlights are required to be on 1/2 hour after sunset to 1/2 hour before sunrise, when visibility is less than 500 feet, or any time the weather conditions require usage of the motor vehicle’s windshield wipers to operate the vehicle in a careful and prudent manner, including in fog.
Montana
Headlights are required to be on 1/2 hour after sunset to 1/2 hour before sunrise, if visibility is less than 500 feet, and in conditions of insufficient light/adverse weather.
Nebraska
Headlights are required to be used from sunset to sunrise, and when visibility is less than 500 feet.
Nevada
Headlights are required to be on 1/2 hour after sunset to 1/2 hour before sunrise, and when visibility is less than 1000 feet.
New Hampshire
Headlights are required to be on 1/2 hour after sundown to 1/2 hour before sunrise, in inclement weather, or when visibility is reduced to less than 1,000 feet.
New Jersey
Headlights are required to be on when wipers are in use, visibility is less than 500 feet, or in conditions of insufficient light/adverse weather.
New Mexico
Headlights are required to be on 1/2 hour after sunset to 1/2 hour before sunrise, and when visibility is less than 500 feet.
New York
Headlights are required to be used 1/2 hour after sunset to 1/2 hour before sunrise, when windshield wipers are being used, when visibility is less than 1000 feet, or when there is insufficient light or adverse weather.
North Carolina
Headlights must be used from sunset to sunrise, when windshield wipers are in use, or when insufficient light limits visibility to 400 feet.
North Dakota
Headlights must be used from sunset to sunrise, when visibility is less than 1000 feet, or when there is insufficient light/adverse weather.
Ohio
Headlights must be used from sunset to sunrise, when wipers are in use, when visibility less than 1000 feet, or in conditions of insufficient light/adverse weather.
Oklahoma
Headlights must be used 1/2 hour after sunset to 1/2 hour before sunrise, when visibility less than 1000 feet, or in conditions of insufficient light/adverse weather.
Pennsylvania
Headlights must be used from sunset to sunrise, when wipers are in use, when visibility is less than 1000 feet, and in conditions of insufficient light/adverse weather. Headlights must be turned on in construction zones. Snow and ice must be removed from a vehicle prior to operation.
Rhode Island
Headlights must be used from sunset to sunrise, in conditions of insufficient light/adverse weather, when wipers are in use, and when visibility is less than 500 feet.
South Carolina
Headlights must be used 1/2 hour after sunset to 1/2 hour before sunrise, when wipers are in use, and when visibility is less than 500 feet.
South Dakota
Headlights must be used 1/2 hour after sunset to 1/2 hour before sunrise, and when visibility is less than 200 feet.
Tennessee
Headlights are required 1/2 hour after sunset to 1/2 hour before sunrise, during fog, smoke, or rain and when visibility is less than 200 feet.
Utah
Headlights are required to be on when visibility is less than 1000 feet or in conditions of insufficient light/adverse weather.
Vermont
Headlights must be used in conditions of insufficient light/adverse weather, or when visibility is less than 500 feet, as well as 30 minutes after sunset and 30 minutes before sunrise.
Virginia
Headlights must be used from sunset to sunrise, when wipers are in use, or when visibility is less than 500 feet.
Washington
Headlights are required to be on 1/2 hour after sunset to 1/2 hour before sunrise, and when visibility is less than 1000 feet.
West Virginia
Headlights must be used from sunset to sunrise, when visibility less than 500 feet, and in conditions of insufficient light/adverse weather.
Wisconsin
Headlights must be used during hours of darkness (effective October 1, 2016, and during periods of limited visibility, unless equipped with daytime running lights).
Wyoming
Headlights are required to be on 1/2 hour after sunset to 1/2 hour before sunrise, when visibility is less than 1000 feet, or in conditions of insufficient light/adverse weather.
British Columbia
Headlights are required to be used 1/2 hour after sunset to 1/2 hour before sunrise, or when visibility is 150m or less.
Manitoba
Headlights are required to be used 1/2 hour after sunset to 1/2 hour before sunrise, or when visibility is 60m or less.
Newfoundland and Labrador
Headlights are to be used one-half hour before sunset to one-half hour after sunrise and when visibility is 150 m or less.
Ontario
Headlights are required to be used 1/2 hour before sunset to 1/2 hour after sunrise or when visibility is limited to 150m or less.
Prince Edward Island
Headlights are required to be used from sunset to sunrise or when visibility is 150m or less. Daytime running lights or headlights are required to be used at all times.
Saskatchewan
Headlight use is required for the period of one-half hour after sunset to one-half hour before sunrise or at any other time when conditions of poor visibility exist.