Worst air pollution Fort McHenry - Baltimore, today and tomorrow
Today (20 September): Air quality in Fort McHenry is fair. AQI and PM2.5 are fair; PM10, NO2, O3, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 11:00 AM (PM2.5: 23.0/100).
Tomorrow (21 September 2026): Air quality in Fort McHenry is good. AQI improves to good; PM2.5 decreases to good; all other pollutants stay as today. Pollution peaks around 12:00 PM (PM2.5: 19.6/100). Airmine updates local air quality forecasts four times daily.
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Given its location — a star-shaped harbor fort surrounded by open waterfront lawn — Fort McHenry shares Baltimore's wider air quality pattern rather than a distinct local one. Checking conditions closer to visit time is still the best way to plan around this specific site.
Today - 20 September | Pollution peaks at 11:00
AQI:
Fair
23.0/100
PM2.5 (fine particles):
Fair
23.0/100
PM10 (coarse particles):
Good
18.5/100
NO2 (nitrogen dioxide):
Good
5.2/100
O3 (ozone):
Good
17.3/100
SO2 (sulfur dioxide):
Good
1.1/100
CO (carbon monoxide):
Good
0.6/100
HCHO (formaldehyde):
Good
2.8/100
PM1 (ultrafine particles):
Good
5.9/100
Levels show the poorest local air quality during the day
Tomorrow - 21 September | Pollution peaks at 12:00
AQI:
Good
19.6/100
PM2.5 (fine particles):
Good
19.6/100
PM10 (coarse particles):
Good
15.4/100
NO2 (nitrogen dioxide):
Good
11.2/100
O3 (ozone):
Good
18.9/100
SO2 (sulfur dioxide):
Good
1.2/100
CO (carbon monoxide):
Good
0.6/100
HCHO (formaldehyde):
Good
3.2/100
PM1 (ultrafine particles):
Good
5.2/100
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Frequently Asked Questions
Is air quality bad in Fort McHenry right now?
On 20 September 2026, overall air quality in Fort McHenry is fair. AQI is the main air quality indicator at 23.0/100. Pollution peaks around 11:00 AM (PM2.5: 23.0/100).
Will air quality be worse tomorrow in Fort McHenry?
On 21 September 2026, air quality conditions in Fort McHenry will be better than today, with AQI forecast at good at 19.6/100. Pollution peaks around 12:00 PM (PM2.5: 19.6/100).
When is air pollution at its worst in Fort McHenry?
Fort McHenry experiences the same seasonal air quality swings as the rest of Baltimore, as winter generally brings the cleanest air, once the summer ozone season has passed; by contrast, extended summer heat waves, often worsened by regional haze, bring the toughest air quality stretch. Dense urban traffic corridors add a persistent background level of pollution that varies less by season than ozone does.
Are air quality levels in Fort McHenry 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 20:27 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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