SmogRank / United States / New York / Rochester

Rochester, month by month

Rochester has a measured daily mean on 1,357 days since 1 January 2023. Its worst month was June 2023, at 77 US AQI (23.3 µg/m³), 206th of 1,603 cities on that month's world ranking. Its cleanest was October 2025, at 21 US AQI (3.8 µg/m³). 2025 averaged 39 US AQI (7.0 µg/m³), against 34 US AQI (6.2 µg/m³) in 2024.

Every month since 2023

Each square is a month's mean PM2.5 in US AQI from Rochester's measured days, with its place on that month's world ranking under it. A month has a mean once 70% of its days are measured, the rule the monthly rankings use; under that, the square gives the days measured. Each square opens that month's ranking with Rochester marked; each year, the year's. A dashed square is the running month, so far.
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

Months without a mean, and why

1 month
MonthWhy
Nov 202511 of 30 days measured; a month needs 21. The others: 19 with under 18 hours of readings or readings that failed our checks.

A day counts once 18 hours of it are measured; a month needs 70% of its days.

Rochester's worst months

MonthUS AQIDays measuredWorld rankEpisode
June 2023 7723.3 µg/m³30 of 30206thof 1,603Eastern United States and Canada, June and July 2023
Eastern United States and Canada, May and June 2023
July 2026 5913.2 µg/m³31 of 31694thof 2,784Northern United States and Canada, July 2026
August 2025 5813.1 µg/m³31 of 31561stof 2,901North-eastern United States and Canada, 29 July to 9 August 2025
July 2023 5712.2 µg/m³31 of 31375thof 1,432United States and Canada, July 2023
Eastern United States and Canada, June and July 2023
February 2026 5410.7 µg/m³28 of 281,253rdof 2,866–
June 2025 5410.5 µg/m³30 of 301,150thof 2,508Northern United States and Canada, May and June 2025

Monthly means over the days measured; finished months only. World rank: its place on that month's world ranking of every city with enough days. Each month opens that ranking.

Rochester's worst days

DayUS AQIEpisode
16 Jul 2026 17995.5 µg/m³Northern United States and Canada, July 2026
30 Jun 2023 17488.9 µg/m³Eastern United States and Canada, June and July 2023
7 Jun 2023 17488.0 µg/m³Eastern United States and Canada, May and June 2023
29 Jun 2023 16677.4 µg/m³Eastern United States and Canada, June and July 2023
28 Jun 2023 16575.4 µg/m³Eastern United States and Canada, June and July 2023
6 Jun 2023 14653.7 µg/m³Eastern United States and Canada, May and June 2023
17 Jul 2023 13549.2 µg/m³United States and Canada, July 2023
4 Aug 2025 12746.0 µg/m³North-eastern United States and Canada, 29 July to 9 August 2025
7 Jun 2025 12645.8 µg/m³Northern United States and Canada, May and June 2025
6 Aug 2025 11440.6 µg/m³North-eastern United States and Canada, 29 July to 9 August 2025

Daily means, the highest since 1 Jan 2023; the WHO's daily guideline is 15 µg/m³. Each date opens that day's world ranking, and each episode the bad-air spell it was part of.

Use this history

SmogRank, PM2.5 monthly and daily means, Rochester, United States, 1 Jan 2023 – 11 Oct 2026. Monitor data from AirNow, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/us/rochester/history (accessed 12 Oct 2026).

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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.

Rochester now: the last 24 hours, its ranks today and the last 12 months day by day.

Updated 2026-10-12 23:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index. Some low-cost readings: Sensor.Community, ODbL (data and licence). Some readings: Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); RMCAB (Secretaría Distrital de Ambiente, Bogotá); Love My Air (City and County of Denver), no reuse terms published (why we use them).