Harrisburg Air Quality in July
Across 2019–2025, Harrisburg's July air quality had a median AQI of 54 (Moderate) over 217 monitored days in the Harrisburg-Carlisle, PA area. 2.3% of July days (5 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 67.7% of days. The cleanest July on record here was 2025 (median AQI 52, 0 days above 100) and the worst was 2023 (median 58, 3 days above 100, peak AQI 113).
- Good: 30.9%
- Moderate: 66.8%
- Unhealthy for Sensitive Groups: 2.3%
- Unhealthy or worse: 0.0%
Reduce Indoor Ozone in Harrisburg
Today's main pollutant in Harrisburg is ground-level ozone (AQI 48). Important: standard HEPA filters do NOT remove ozone — only a purifier with a substantial activated-carbon bed adsorbs it. The biggest wins are cutting indoor sources (gas appliances, certain "ionizer" purifiers) and ventilating when outdoor ozone is low (early morning). A high-carbon unit helps with the gases and VOCs that linger indoors.
Recommended: Levoit Core 300 — True HEPA + activated carbon · CADR ~141 CFM · rooms up to 219 sq ft
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How is the air in Harrisburg in July?
Moderate on a typical day: median AQI 54 across 2019–2025, with 2.3% of July days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓30.9% of July days were Good (AQI 0–50), 66.8% Moderate (51–100).
- ✓5 days of 217 reached AQI 101+; the July peak was 127.
- ✓Best July: 2025; worst July: 2023.
Frequently asked questions
What is the air quality like in Harrisburg in July?▾
Across 2019–2025, the median daily AQI in Harrisburg in July was 54 (Moderate). 30.9% of days were Good, 66.8% Moderate, and 2.3% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is July a good time for outdoor exercise in Harrisburg?▾
A typical July day in Harrisburg is Moderate (median AQI 54): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 43 of July days (2.3%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Harrisburg's July air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 67.7% of July days in Harrisburg. The highest July AQI recorded in 2019–2025 was 127 (Unhealthy for Sensitive Groups), in 2023.
Harrisburg July air quality, year by year
Harrisburg July air quality by year (Harrisburg-Carlisle, PA, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 54 | 0 | 77 | PM2.5 |
| 2020 | 31 | 55 | 0 | 80 | PM2.5 |
| 2021 | 31 | 57 | 2 | 127 | PM2.5 |
| 2022 | 31 | 53 | 0 | 80 | PM2.5 |
| 2023worst | 31 | 58 | 3 | 113 | PM2.5 |
| 2024 | 31 | 54 | 0 | 87 | O3 |
| 2025cleanest | 31 | 52 | 0 | 71 | PM2.5 |
What July air means in Harrisburg
A typical July day in Harrisburg is Moderate (median AQI 54): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 43 of July days (2.3%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
July's median AQI of 54 is above Harrisburg's whole-year median of 50, making it one of the area's dirtier periods. Nationally, the median July AQI across every EPA metro area (103,858 metro-days, 2019–2025) is 47, so Harrisburg runs above the national July norm; 2.3% of its July days topped AQI 100 versus 3.6% nationally (below average).
July is part of Harrisburg's summer season (June, July, August); the summer page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Harrisburg
The latest EPA AirNow observation puts Harrisburg's AQI at 48 (O3). The figures above are multi-year month statistics, not today's reading.
View current Harrisburg air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Harrisburg-Carlisle, PA), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.