Current Air Quality Index & Pollutant Levels
Pennsylvania, United States
Daily air quality forecast. PM2.5, PM10, O₃, NO₂, SO₂, CO.
Air Quality
56
Sensitive groups (children, elderly, those with respiratory conditions) may experience symptoms. Consider reducing prolonged outdoor exertion.
μg/m³
Hourly forecast
AQI · PM2.5 μg/m³
18:005610
19:005110
20:004614
21:003817
22:003618
23:004020
00:004321
01:004822
02:005824
03:006127
04:006229
05:006431
06:006633
07:006836
08:006937
09:006936
10:006937
11:006835
12:006630
13:006625
14:006619
15:006415
16:006312
17:006211
PM2.5
9.7μg/m³
64% of WHO limitAcceptable
PM10
9.7μg/m³
22% of WHO limitGood
Ozone (O₃)
124.4μg/m³
124% of WHO limitExceeded
NO₂
6.2μg/m³
25% of WHO limitGood
SO₂
1.8μg/m³
4% of WHO limitGood
CO
236.0μg/m³
6% of WHO limitGood
Daily air quality forecast
Today45Moderate36–56
Thu58Moderate32–69
Fri46Moderate29–64
Sat39Fair27–60
Sun38Fair22–58
European AQI Scale
0–20
Good
Air pollution poses little or no risk.
21–40
Fair
Acceptable for most; very sensitive people may notice symptoms.
41–60
Moderate
Children, elderly and people with conditions should limit prolonged outdoor exertion.
61–80
Poor
Everyone may start to feel effects; sensitive groups risk more serious effects.
81–100
Very Poor
Health warning of emergency conditions; everyone is more likely to be affected.
100+
Hazardous
Health alert: serious effects for everyone — limit time outdoors.
The European Air Quality Index ranges from 0 (best) to 100+ (worst). It combines measurements of particulate matter and gas pollutants into a single number.
History — Past 30 days
min–max Avg AQI
What are these pollutants?
PM2.5 — Fine particulate matter smaller than 2.5 micrometers. These particles are small enough to bypass the nose and throat, reaching deep into the lungs and even entering the bloodstream. Major sources include vehicle exhaust, industrial processes, and wildfires.
PM10 — Coarse particles smaller than 10 micrometers, including dust, pollen, and road surface wear. While larger than PM2.5, they still cause respiratory irritation and aggravate asthma.
O₃ — Ground-level ozone is not emitted directly — it forms when nitrogen oxides and volatile organic compounds react in sunlight. Higher in summer afternoons. Can trigger asthma attacks and reduce lung function.
NO₂ — Nitrogen dioxide comes primarily from vehicle engines and power plants. It inflames the lining of the airways, making the lungs more susceptible to infection.
SO₂ — Sulfur dioxide is released by burning fossil fuels containing sulfur, especially coal and oil. Even short exposure can constrict airways, particularly in people with asthma.
CO — Carbon monoxide is an odorless gas from incomplete combustion of fuels. Outdoors, it mainly comes from vehicle traffic. At elevated levels, it reduces the blood's ability to carry oxygen.
Dust (AOD) — AOD at 550nm. Above 0.3 = Saharan dust.
Air Quality FAQ
What is the Air Quality Index?
The European AQI is a number from 0 to 100+ that summarizes how clean or polluted the air is. It combines measurements of fine particles (PM2.5, PM10) and gases (ozone, NO₂, SO₂) into a single score. The higher the number, the worse the air quality and the greater the health risk.
Who is most sensitive to air pollution?
Children, the elderly, pregnant women, and people with asthma, COPD, or heart disease are most vulnerable. Even moderate pollution levels (AQI 41–60) can trigger symptoms in these groups. Athletes and outdoor workers also face higher exposure due to increased breathing rates.
How can I protect myself?
On high-pollution days: stay indoors with windows closed, use air purifiers with HEPA filters, avoid strenuous outdoor exercise (especially near busy roads), and check the AQI forecast before planning activities. Even on moderate days, sensitive individuals should limit prolonged outdoor exertion.
When is air quality typically worst?
Ozone peaks on hot, sunny afternoons (summer). Particle pollution (PM2.5) is often worst in winter due to heating and temperature inversions that trap pollutants near the ground. Rush-hour traffic causes NO₂ spikes morning and evening. Dust events and wildfires can cause sudden, severe spikes any time of year.
Data: Copernicus CAMS · CC-BY-4.0
Air quality nearby