Worst air pollution Germantown - Penn Knox - Philadelphia, today and tomorrow
Today (20 September): Air quality in Germantown - Penn Knox is moderate. AQI and NO2 are moderate; PM2.5, O3, and PM1 are fair; PM10, SO2, CO, and HCHO are good. Pollution peaks around 2:00 PM (NO2: 40.6/100).
Tomorrow (21 September 2026): Air quality in Germantown - Penn Knox is moderate. PM2.5 decreases to good; PM1 decreases to good; all other pollutants stay as today. Pollution peaks around 3:00 PM (NO2: 41.5/100). Airmine updates local air quality forecasts four times daily.
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Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team
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In Germantown - Penn Knox, dense traffic and everyday urban activity are the main drivers of local particulate matter and nitrogen dioxide levels. Vegetation nearby provides a modest natural filter for airborne particulates. Actual air quality on a given day still depends heavily on local wind and weather conditions. Day-to-day readings still shift with wind direction, traffic volume, and weather conditions.
Today - 20 September | Pollution peaks at 14:00
AQI:
Moderate
40.6/100
PM2.5 (fine particles):
Fair
25.9/100
PM10 (coarse particles):
Good
16.5/100
NO2 (nitrogen dioxide):
Moderate
40.6/100
O3 (ozone):
Fair
23.4/100
SO2 (sulfur dioxide):
Good
1.1/100
CO (carbon monoxide):
Good
0.6/100
HCHO (formaldehyde):
Good
2.7/100
PM1 (ultrafine particles):
Fair
38.0/100
Levels show the poorest local air quality during the day
Tomorrow - 21 September | Pollution peaks at 15:00
AQI:
Moderate
41.5/100
PM2.5 (fine particles):
Good
17.0/100
PM10 (coarse particles):
Good
12.6/100
NO2 (nitrogen dioxide):
Moderate
41.5/100
O3 (ozone):
Fair
29.7/100
SO2 (sulfur dioxide):
Good
2.1/100
CO (carbon monoxide):
Good
0.6/100
HCHO (formaldehyde):
Good
3.8/100
PM1 (ultrafine particles):
Good
19.3/100
Other Landmarks in Philadelphia
Sports venues in Philadelphia
Frequently Asked Questions
Is air quality bad in Germantown - Penn Knox right now?
On 20 September 2026, overall air quality in Germantown - Penn Knox is moderate. AQI is the main air quality indicator at 40.6/100. Pollution peaks around 2:00 PM (NO2: 40.6/100).
Will air quality be worse tomorrow in Germantown - Penn Knox?
On 21 September 2026, air quality conditions in Germantown - Penn Knox will be similar to today, with AQI forecast at moderate at 41.5/100. Pollution peaks around 3:00 PM (NO2: 41.5/100).
When is air pollution at its worst in Germantown - Penn Knox?
This part of the city typically experiences its worst air quality during the coldest months, as reduced winter air mixing lets traffic and heating emissions accumulate close to the ground. The warmer months shift the main air quality risk here toward ground-level ozone, as heat and sunlight react with traffic-sourced emissions to drive photochemical smog.
Are air quality levels in Germantown - Penn Knox based on measurements or forecasts?
It is forecasts derived by downscaling forecasts provided by EU’s Copernicus Atmosphere Monitoring Service (CAMS) by taking into account local conditions such as traffic patterns. CAMS bases its forecast on satellite measurements of particles and chemical compounds in the atmosphere. Airmine’s services were developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team.
Why doesn’t the forecast always reflect wildfire impacts?
Airmine’s forecast uses CAMS (Copernicus Atmosphere Monitoring Service) as its background atmospheric model. While CAMS includes wildfire emissions, these are derived from satellite observations and are not available in real time. During rapidly evolving wildfire events, there may therefore be a delay before increased emissions are incorporated into the model. As a result, the forecast may temporarily underestimate PM₂.₅ and other pollutants associated with wildfire smoke.
During rapidly evolving wildfire events, CAMS may lag by approximately 1–2 days before increased wildfire emissions are fully represented, which can lead to temporary underestimation of PM₂.₅ concentrations in Airmine’s forecast.
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Data provided by Airmine — Last update: 20 September 2026 at 14:33 CEST (Data is updated four times daily.)
This forecast is produced independently using Airmine's own atmospheric data and models.
Unless explicitly made clear, the content on this site has not been paid for by external organisations and is Airmine's sole responsibility.
Disclaimer: Forecasts are provided for informational purposes only and should not be relied upon as medical advice. Actual pollen and air quality conditions may vary from the forecast. If you have allergies, asthma, or another medical condition, consult a healthcare professional. Please see our Terms of Service for important information about limitations of liability.
Some text on this page may be generated or summarised using artificial intelligence (AI). Wherever possible, AI-generated content is enriched with Airmine's proprietary data to improve its accuracy and relevance. However, AI-generated content may still contain errors, omissions, or inaccuracies.
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