PM2.5 in Rochester, NY

Rochester Air Quality Record, 2019–2025

EPA publishes one daily AQI value per metropolitan area — the highest value any regulatory monitor in the area reported that day. For Rochester that area is Rochester, NY. In 2025 monitors there reported air quality on 365 days, with a median AQI of 39, a 90th-percentile AQI of 61 and a worst day of 135. 7 of those days reached AQI 101 or higher (Unhealthy for Sensitive Groups or worse).

Across 2019–2025, Rochester's air worsened: the area's median AQI held near 42 and days above AQI 100 rose from about 0 to 6 per year (comparing the earlier and later halves of the period).

Source: EPA Air Quality System (AQS) pre-generated Annual AQI by CBSA files, https://aqs.epa.gov/aqsweb/airdata/download_files.html (retrieved 2026-09-07). Area: Rochester, NY (Core Based Statistical Area 40380).

How often is PM2.5 the main pollutant in Rochester?

Across 2019–2025, PM2.5 was the pollutant that set the daily AQI on 1374 of 2557 measured days in the Rochester, NY area — about 54% of the time. In 2025 alone it led on 141 days. A pollutant "leads" when its own AQI sub-index is the highest of the day, so this is a direct measure of which pollution problem dominates locally.

About Fine Particulate Matter

Tiny particles less than 2.5 micrometers that can penetrate deep into lungs and bloodstream.

Measured in µg/m³.

What is a safe level of PM2.5?

By the EPA Air Quality Index, fine particulate matter is Good — safe for everyone up to 9 µg/m³ (AQI 50). Between that and 35.4 µg/m³ (AQI 100) the air is Moderate: fine for most people, but unusually sensitive individuals may notice symptoms. Above 35.4 µg/m³ the AQI enters Unhealthy for Sensitive Groups and EPA health guidance begins.

What each AQI level means for PM2.5

• 0–50 GoodAir quality is considered satisfactory, and air pollution poses little or no risk.
• 51–100 ModerateAir quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.
• 101–150 Unhealthy for Sensitive GroupsMembers of sensitive groups may experience health effects. The general public is not likely to be affected.
• 151–200 UnhealthyEveryone may begin to experience health effects; members of sensitive groups may experience more serious health effects.
• 201–300 Very UnhealthyHealth warnings of emergency conditions. The entire population is more likely to be affected.
• 301–500 HazardousHealth alert: everyone may experience more serious health effects.