What does the weather term "haze" mean?

The weather term “haze” refers to pollution of salt, dust and fine particles that are dispersed through parts of a specific area’s atmosphere. Individually, these particles are invisible, but when grouped together, they form a haze that diminishes visibility.

In certain areas of high elevation in the western parts of the United States, concentrations of high ozone are present during the colder months with increased levels of NOx and VOC emissions. When temperatures are close to or near freezing with snow on the ground, these emissions cause ozone to form, which is a major contributing factor to haze or smog.