Is bursting firecrackers in rainy weather worse?

When fireworks go off on a cloudy and high humidity day, the air in a particular location is likely to become more polluted. This is due to a combination of pollutants emitted by fireworks and prevailing weather conditions that trap these pollutants closer to the ground.

Fireworks release various harmful substances into the atmosphere. These include particulate matter (PM), carbon dioxide, carbon monoxide, nitrogen oxides and sulfur dioxide. These emissions can combine to create a toxic smog, significantly reducing air quality and visibility.

Cloudy skies generally lead to cooler days and lower mixing altitude, which is the atmospheric layer where pollutants can disperse. When this height is lower, pollutants are trapped closer to the ground, leading to higher concentrations. Most fog events therefore coincide with cloudy skies.

Higher humidity makes the problem worse. Water vapor in the air can interact with pollutants to form secondary pollutants. For example, sulfur dioxide and nitrogen oxides can mix with steam to form acid rain. High humidity can also lead to the formation of fog and haze, which can trap PM and other pollutants and prevent them from dispersing.