Haze is an atmospheric phenomenon where dust, smoke, and dry particles in the air obscure the skys clarity. It often occurs when suspended dust and smoke particles accumulate in relatively dry air, and weather conditions block the dispersal of smoke and other pollutants, causing them to concentrate and form a low-hanging shroud that impairs visibility. Haze can have a bluish or brownish tint, depending on the direction of view.

Haze is different from mist and fog, which are also atmospheric phenomena that affect visibility. Mist and fog differ by how far you can see through them. Fog is when you can see less than 1,000 meters away, and if you can see further than 1,000 meters, it is called mist. Mist is still the result of the suspension of water droplets, but simply at a lower density. Haze, on the other hand, is a suspension of extremely small, dry particles in the air, not water droplets.

Haze can be created through various activities such as farming, vehicle traffic, and wildfires, which can create a pollutant-clouded atmosphere. Wet haze, or visibility-reducing aerosols of the wet type, can occur when some of the particles in haze create condensation, subsequently giving form to mist droplets. The process of aerosol creation occurs due to the chemical reactions between the atmosphere and the sulfur dioxide gas emissions, which create small droplets of sulfuric acid. Sunlight, high humidity, and stagnant airflow may enhance this process.

Haze can hinder visibility and cause respiratory health threats if excessively inhaled. It can also obscure weather hazards, such as low-level cloud formations associated with thunderstorms.