When should you avoid using high-beam headlights?

Using high-beam headlights is not advisable in conditions like fog, snow, or rain because these weather phenomena can scatter the light, reducing visibility. High beams produce a stronger illumination that can reflect off the moisture in the air, creating a glare that may actually hinder a driver’s ability to see clearly. Instead, low-beam headlights are more effective in such conditions as they provide sufficient light without causing excessive glare.

In addition to being inappropriate for inclement weather, high beams are generally not used during daylight, in urban areas, or in clear conditions when other vehicles are present. In clear weather, while it's technically acceptable, low beams are often adequate for visibility and more considerate to others on the road.