SmogRank / United States / Pennsylvania / Harrisburg

Harrisburg, month by month

Harrisburg has a measured daily mean on 1,360 days since 1 January 2023. Its worst month was June 2023, at 97 US AQI (33.6 µg/m³), 57th of 1,603 cities on that month's world ranking. Its cleanest was October 2025, at 26 US AQI (4.7 µg/m³). 2025 averaged 46 US AQI (8.2 µg/m³), against 47 US AQI (8.5 µg/m³) in 2024.

Every month since 2023

Each square is a month's mean PM2.5 in US AQI from Harrisburg'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 Harrisburg marked; each year, the year's. A dashed square is the running month, so far.
Good0–50
Moderate51–100
Unhealthy for 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

Harrisburg's worst months

MonthUS AQIDays measuredWorld rankEpisode
June 2023 9733.6 µg/m³29 of 3057thof 1,603Eastern United States and Canada, June and July 2023
United States and Canada, June 2023and 1 more
July 2026 7320.8 µg/m³30 of 31306thof 2,784Northern United States and Canada, July 2026
February 2026 6114.4 µg/m³28 of 28815thof 2,866North-eastern United States and Canada, 14 to 19 February 2026
Pennsylvania, United States, February 2026
July 2023 6013.8 µg/m³31 of 31219thof 1,432United States and Canada, July 2023
North-eastern United States, 19 July 2023and 1 more
December 2023 5812.7 µg/m³31 of 31379thof 2,247Pennsylvania, New Jersey and Massachusetts, United States, December 2023
North-eastern United States, December 2023
January 2023 5511.3 µg/m³31 of 31377thof 1,261–

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.

Harrisburg's worst days

DayUS AQIEpisode
8 Jun 2023 270195.0 µg/m³Eastern United States and Canada, May and June 2023
17 Jul 2026 228153.0 µg/m³Northern United States and Canada, July 2026
7 Jun 2023 223148.0 µg/m³Eastern United States and Canada, May and June 2023
16 Jul 2026 18299.1 µg/m³Northern United States and Canada, July 2026
29 Jun 2023 17995.6 µg/m³Eastern United States and Canada, June and July 2023
18 Jul 2026 17183.9 µg/m³Northern United States and Canada, July 2026
30 Jun 2023 16677.0 µg/m³Eastern United States and Canada, June and July 2023
6 Jun 2023 14051.2 µg/m³Eastern United States and Canada, May and June 2023
28 Jun 2023 13850.7 µg/m³Eastern United States and Canada, June and July 2023
1 Jul 2023 11240.1 µg/m³Eastern United States and Canada, June and July 2023

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, Harrisburg, 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/harrisburg/history (accessed 13 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.

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

Updated 2026-10-13 03:07 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).