Harrisburg Air Quality in April
Across 2019–2025, Harrisburg's April air quality had a median AQI of 46 (Good) over 210 monitored days in the Harrisburg-Carlisle, PA area. 1.0% of April days (2 of 210) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 55.2% of days. The cleanest April on record here was 2025 (median AQI 41, 0 days above 100) and the worst was 2023 (median 54, 1 day above 100, peak AQI 101).
- Good: 55.7%
- Moderate: 43.3%
- Unhealthy for Sensitive Groups: 0.5%
- Unhealthy or worse: 0.5%
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 April?
Good on a typical day: median AQI 46 across 2019–2025, with 1.0% of April days above AQI 100. Ground-level ozone is the main driver.
- ✓55.7% of April days were Good (AQI 0–50), 43.3% Moderate (51–100).
- ✓2 days of 210 reached AQI 101+; the April peak was 161.
- ✓Best April: 2025; worst April: 2023.
Frequently asked questions
What is the air quality like in Harrisburg in April?▾
Across 2019–2025, the median daily AQI in Harrisburg in April was 46 (Good). 55.7% of days were Good, 43.3% Moderate, and 1.0% reached Unhealthy for Sensitive Groups or worse, based on 210 monitored days in EPA's Air Quality System.
Is April a good time for outdoor exercise in Harrisburg?▾
A typical April day in Harrisburg sits in the Good range (median AQI 46), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 100 of April days (1.0%) reached AQI 101+ in 2019–2025.
Which pollutant causes Harrisburg's April air quality problems?▾
Ground-level ozone set the daily AQI on 55.2% of April days in Harrisburg. The highest April AQI recorded in 2019–2025 was 161 (Unhealthy), in 2023.
Harrisburg April air quality, year by year
Harrisburg April air quality by year (Harrisburg-Carlisle, PA, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 30 | 52 | 1 | 161 | PM2.5 |
| 2020 | 30 | 44 | 0 | 66 | O3 |
| 2021 | 30 | 53 | 0 | 73 | PM2.5 |
| 2022 | 30 | 45 | 0 | 64 | O3 |
| 2023worst | 30 | 54 | 1 | 101 | O3 |
| 2024 | 30 | 47 | 0 | 73 | O3 |
| 2025cleanest | 30 | 41 | 0 | 80 | O3 |
What April air means in Harrisburg
A typical April day in Harrisburg sits in the Good range (median AQI 46), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 100 of April days (1.0%) reached AQI 101+ in 2019–2025.
April's median AQI of 46 is below Harrisburg's whole-year median of 50, making it one of the area's cleaner periods. Nationally, the median April AQI across every EPA metro area (100,677 metro-days, 2019–2025) is 44, so Harrisburg runs in line with the national April norm; 1.0% of its April days topped AQI 100 versus 0.7% nationally (about the same).
April is part of Harrisburg's spring season (March, April, May); the spring 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.