Harrisburg Air Quality in Spring
Across 2019–2025, Harrisburg's spring (March–May) air quality had a median AQI of 46 (Good) over 644 monitored days in the Harrisburg-Carlisle, PA area. 0.5% of spring days (3 of 644) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 50.9% of days. The cleanest spring on record here was 2025 (median AQI 41, 0 days above 100) and the worst was 2019 (median 52, 2 days above 100, peak AQI 161).
- Good: 59.6%
- Moderate: 39.9%
- Unhealthy for Sensitive Groups: 0.3%
- Unhealthy or worse: 0.2%
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 spring?
Good on a typical day: median AQI 46 across 2019–2025, with 0.5% of spring days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓59.6% of spring days were Good (AQI 0–50), 39.9% Moderate (51–100).
- ✓3 days of 644 reached AQI 101+; the spring peak was 161.
- ✓Cleanest month: May; worst month: April.
Frequently asked questions
What is the air quality like in Harrisburg in spring?▾
Across 2019–2025, the median daily AQI in Harrisburg in spring was 46 (Good). 59.6% of days were Good, 39.9% Moderate, and 0.5% reached Unhealthy for Sensitive Groups or worse, based on 644 monitored days in EPA's Air Quality System.
Is spring a good time for outdoor exercise in Harrisburg?▾
A typical spring 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; fewer than 1% of spring days reached AQI 101+ in 2019–2025.
Which pollutant causes Harrisburg's spring air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 50.9% of spring days in Harrisburg. The highest spring AQI recorded in 2019–2025 was 161 (Unhealthy), in 2019.
Harrisburg spring air quality, year by year
Harrisburg spring air quality by year (Harrisburg-Carlisle, PA, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019worst | 92 | 52 | 2 | 161 | PM2.5 |
| 2020 | 92 | 44 | 0 | 67 | PM2.5 |
| 2021 | 92 | 46 | 0 | 100 | PM2.5 |
| 2022 | 92 | 47 | 0 | 74 | PM2.5 |
| 2023 | 92 | 51 | 1 | 101 | O3 |
| 2024 | 92 | 43 | 0 | 77 | O3 |
| 2025cleanest | 92 | 41 | 0 | 80 | O3 |
What spring air means in Harrisburg
A typical spring 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; fewer than 1% of spring days reached AQI 101+ in 2019–2025.
Spring'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 Spring AQI across every EPA metro area (307,196 metro-days, 2019–2025) is 43, so Harrisburg runs in line with the national Spring norm; 0.5% of its Spring days topped AQI 100 versus 0.8% nationally (about the same).
Within the season, May is the cleanest month (median AQI 44, 0.0% of days above 100) and April the worst (median 46, 1.0% above 100).
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 season 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.