Did you know that Tennessee state law requires you to have your headlights on while driving in rainy conditions? The law not only states you must have headlights on during rain, but in mist and other types of precipitation including snow. Lt. Bill Miller with the Tennessee Highway Patrol says the best rule to remember this is when your windshield wipers are working, your headlights should be on. This is for your safety as well as other motorists who can see you better approaching you in an opposite direction or from behind.