What term describes phenomena in the atmosphere that reduces horizontal visibility but is not precipitation?

The correct term that describes phenomena in the atmosphere that reduces horizontal visibility but is not precipitation is obscuration. Obscuration encompasses various atmospheric conditions, such as fog and haze, that affect visibility without the presence of precipitation.

While fog is indeed a specific type of obscuration characterized by dense water vapor that significantly reduces visibility, not all obscuration is fog. Haze refers to the presence of fine particles or pollutants that can also reduce visibility, but it is distinct from fog in that it does not involve condensation of water vapor. Cloud cover, on the other hand, refers to the amount of cloud present in the sky, which can obscure the view but does not typically impact horizontal visibility on the ground the same way that obscuration does. Thus, obscuration serves as the broader term that includes these specific conditions and captures the essence of reduced visibility phenomena without further classification into subtypes.