New Year’s Eve marks one of the most widely celebrated nights of the year around the world, with fireworks displays lighting up skies across major cities, towns, and rural communities. While these celebrations are brief, their impact on air quality is immediate and measurable.
Air pollution from fireworks occurs almost simultaneously across thousands of locations worldwide. Within minutes after midnight, fine particulate matter and other pollutants are released into the air, leading to short but intense pollution events that can affect entire metropolitan regions.
These pollution spikes are especially concerning from a public health perspective because they often coincide with winter weather conditions that limit the atmosphere’s ability to disperse pollutants (1).
How do fireworks affect air quality?
Fireworks rely on combustion and metal-based compounds to create color, light, and sound. When ignited, they release dense smoke made up of fine and ultrafine particles along with a mix of chemical pollutants.
- Fine particulate matter such as PM2.5 and ultrafine particles that can penetrate deep into the lungs.
- Metal compounds including barium, strontium, aluminum, copper, magnesium, and potassium.
- Combustion-related gases such as sulfur dioxide and nitrogen oxides.
Scientific studies show that many of these particles shift into smaller, more respirable sizes during fireworks events, increasing the potential for inhalation and short-term health impacts (2).
How severe can pollution spikes be?
Air quality monitoring around major fireworks events consistently shows sharp increases in PM2.5 concentrations. Research indicates that fine particle levels often rise by 30 to 60 percent above typical background levels in the hours following midnight, with even higher spikes observed during large or widespread celebrations (3).
These short-lived events can push air quality into the unhealthy for sensitive groups range and, at times, into unhealthy levels, even in places that usually experience relatively clean air.
Health-based guidelines from the World Health Organization emphasize that there is no completely safe level of exposure to fine particulate matter. Even brief spikes above recommended limits can place stress on the heart and lungs, particularly for vulnerable populations (4).
Air quality conditions across the United States
In the United States, air quality ranged from moderate to unhealthy in the hours following midnight.
Air quality map of USA on 1 Jan, 2026, at 3 AM PT). Source: IQAir
Cities in the moderate range included New York City, where AQI remained around 60.
Several cities entered the unhealthy for sensitive groups range, with Phoenix reaching AQI values just above 100.
Unhealthy air quality was observed in multiple regions. New Orleans and St. Louis recorded AQI levels around 140, while Houston reached the mid-150s. Tacoma and Salt Lake City also fell into the unhealthy category, with AQI values in the low-to-mid 100s.
A small number of cities experienced more severe conditions. Tampa recorded AQI values approaching 190, and San Antonio reached the low 200s, representing the highest levels observed among major U.S. cities during this period.
Air quality conditions across Europe
Across Europe, air quality conditions around midnight also varied by city, with locations ranging from moderate air quality to unhealthy levels for short periods.
Air quality map of Central Europe on 31 Dec, 2025, at 7 PM PT). Source: IQAir
Cities remaining in the moderate range included London, where AQI reached the high 80s, and Madrid, which recorded AQI values in the low 80s.
Several cities entered the unhealthy for sensitive groups category. Paris recorded AQI values just above 100, while Belgrade reached the low 110s, indicating elevated pollution levels that may affect children, older adults, and people with respiratory conditions.
Unhealthy air quality was observed in a smaller number of cities. Berlin experienced a brief spike, peaking at an AQI of 168 for approximately one hour. Milan recorded one of the highest readings in Europe, reaching AQI levels in the mid-180s.
The takeaway
New Year’s Eve fireworks create moments of celebration, but they also trigger predictable and measurable declines in air quality across large areas in a very short time. Although these pollution events are temporary, the fine particles and chemical compounds released can pose real health risks, particularly for children, older adults, and people with existing heart or lung conditions.
From a public health perspective, understanding the air quality impacts of fireworks allows individuals and communities to make informed choices. Monitoring air quality, limiting outdoor exposure during peak pollution hours, and considering lower-emission celebration alternatives can help reduce health risks while preserving the spirit of the occasion (5).
Personal protection from poor air
Even if you avoid using fireworks, air quality may still worsen due to widespread fireworks activity nearby. Pollution levels often peak shortly after midnight and can affect both outdoor and indoor air.
To reduce exposure during fireworks-related pollution events:
- Use a free air quality app for real-time alerts and forecasts.
- Avoid outdoor activity during peak fireworks hours.
- Shut doors and windows and set HVAC systems to recirculate indoor air.
- Run a high-performance air purifier to filter particles, gases, and other pollutants.
