The following states require headlights to be on when wipers are in use due to rain, sleet, or snow: Alabama, Arkansas, California, Delaware, Illinois, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Missouri, Nebraska, New Jersey, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Carolina, Tennessee, and Virginia. Interestingly, New York says daytime running lights aren’t enough, and that the same low beams used for night driving must be on in wet conditions. Then, some states really get down to brass tacks and outline that intermittent misting doesn’t require headlight use.
Some states’ laws don’t explicitly state that headlights must be on when wipers are on, but still have it covered with any form of wet or inclement weather — particularly our visibility-killing friend, fog — or when there is not sufficient light. Or, “unfavorable atmospheric conditions,” as Utah and a few other states describe it. These include Alaska, Arizona, Connecticut, Florida, Georgia, Hawaii, Idaho, Indiana, Iowa, Michigan, Minnesota, Mississippi, Montana, Nevada, New Hampshire, North Dakota, Oregon, South Dakota, Texas, Utah, Vermont, Washington, West Virginia, Wisconsin, Wyoming.
It’s worth noting that the Colorado State Patrol says headlights are not required in the rain, while New Mexico only has a statute concerning the use of headlights in conditions where there is “not sufficient light to render clearly discernible persons and vehicles on the highway at a distance of five hundred feet ahead.”
