What is a good rule of thumb for knowing when to turn on your headlights?

Turning on your headlights when you need your windshield wipers is a good practice because it enhances your visibility while driving in adverse weather conditions. When it's raining, visibility can be significantly reduced due to both the rain itself and the muddy water that can splash onto your windshield. By using your headlights, you not only improve your ability to see the road and other vehicles, but you also make your vehicle more visible to others on the road. This is particularly important in conditions where rain may obscure your view and compromise safety.

In addition to this practice, headlights can also help to reduce accidents during poor weather conditions by ensuring that you are seen by other drivers. It is essential to use both your wipers and headlights together whenever visibility is compromised, thus maintaining safety for all road users.