Worst air pollution Ellicott City, today and tomorrow
Today (16 July): Air quality in Ellicott City is fair. AQI and O3 are fair; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 1:00 PM (O3: 35.2/100).
Tomorrow (17 July 2026): Air quality in Ellicott City is fair. All pollutants stay as today. Pollution peaks around 12:00 PM (O3: 39.5/100). 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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Ellicott City's air quality benefits from the Howard County Maryland Piedmont position between Baltimore and Washington DC, with vehicle emissions from US-29 and I-70 contributing local sources in this unincorporated community. The Patuxent River valley and the surrounding Maryland Piedmont hills provide topographic variation and some natural ventilation, while the broader Baltimore-Washington mid-Atlantic regional airshed contributes elevated summer ozone from both cities' combined vehicle traffic throughout the summer ozone season.
Today - 16 July | Pollution peaks at 13:00
AQI:
Fair
35.2/100
PM2.5 (fine particles):
Good
12.9/100
PM10 (coarse particles):
Good
8.6/100
NO2 (nitrogen dioxide):
Good
9.9/100
O3 (ozone):
Fair
35.2/100
SO2 (sulfur dioxide):
Good
1.4/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
4.5/100
PM1 (ultrafine particles):
Good
8.9/100
Levels show the poorest local air quality during the day
Tomorrow - 17 July | Pollution peaks at 12:00
AQI:
Fair
39.5/100
PM2.5 (fine particles):
Good
16.0/100
PM10 (coarse particles):
Good
10.1/100
NO2 (nitrogen dioxide):
Good
9.6/100
O3 (ozone):
Fair
39.5/100
SO2 (sulfur dioxide):
Good
1.6/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
4.6/100
PM1 (ultrafine particles):
Good
10.3/100
Pollen forecast in Ellicott City
View pollen forecastFrequently Asked Questions
Is air quality bad in Ellicott City right now?
On 16 July 2026, overall air quality in Ellicott City is fair. AQI is the main air quality indicator at 35.2/100. Pollution peaks around 1:00 PM (O3: 35.2/100).
Will air quality be worse tomorrow in Ellicott City?
On 17 July 2026, air quality conditions in Ellicott City will be similar to today, with AQI forecast at fair at 39.5/100. Pollution peaks around 12:00 PM (O3: 39.5/100).
When is air pollution at its worst in Ellicott City?
Ellicott City experiences a distinct seasonal swing in air quality. In short, the cleanest stretch of the year usually comes in winter, whereas summer heat waves bring the highest ozone risk, compounded by pollution drifting in from the wider region. Dense urban traffic corridors add a persistent background level of pollution that varies less by season than ozone does.
Are air quality levels in Ellicott City 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.
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Data provided by Airmine — Last update: 16 July 2026 at 10:33 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.
For long term forecasts and maps, see the Airmine app