Worst air pollution Norwalk, today and tomorrow
Today (9 August): Air quality in Norwalk is fair. AQI and O3 are fair; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 11:00 AM (O3: 35.1/100).
Tomorrow (10 August 2026): Air quality in Norwalk is fair. All pollutants stay as today. Pollution peaks around 12:00 PM (O3: 32.4/100). 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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Norwalk's air quality in Connecticut reflects the lower Housatonic River valley at Long Island Sound, with vehicle emissions from I-95 and the Merritt Parkway and surrounding mixed commercial and residential character contributing local sources. The Long Island Sound coastal position provides maritime ventilation, while the broader New York metropolitan area's regional ozone and PM2.5 on prevailing southwesterly winds elevates background pollution above the Connecticut coastal baseline throughout the summer.
Today - 9 August | Pollution peaks at 11:00
AQI:
Fair
35.1/100
PM2.5 (fine particles):
Good
9.9/100
PM10 (coarse particles):
Good
3.1/100
NO2 (nitrogen dioxide):
Good
9.1/100
O3 (ozone):
Fair
35.1/100
SO2 (sulfur dioxide):
Good
1.6/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
4.2/100
PM1 (ultrafine particles):
Good
11.1/100
Levels show the poorest local air quality during the day
Tomorrow - 10 August | Pollution peaks at 12:00
AQI:
Fair
32.4/100
PM2.5 (fine particles):
Good
10.3/100
PM10 (coarse particles):
Good
5.2/100
NO2 (nitrogen dioxide):
Good
15.5/100
O3 (ozone):
Fair
32.4/100
SO2 (sulfur dioxide):
Good
1.6/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
4.5/100
PM1 (ultrafine particles):
Good
11.5/100
Pollen forecast in Norwalk
View pollen forecastFrequently Asked Questions
Is air quality bad in Norwalk right now?
On 9 August 2026, overall air quality in Norwalk is fair. AQI is the main air quality indicator at 35.1/100. Pollution peaks around 11:00 AM (O3: 35.1/100).
Will air quality be worse tomorrow in Norwalk?
On 10 August 2026, air quality conditions in Norwalk will be similar to today, with AQI forecast at fair at 32.4/100. Pollution peaks around 12:00 PM (O3: 32.4/100).
When is air pollution at its worst in Norwalk?
Conditions in Norwalk vary noticeably across the seasons. Typically, the shoulder seasons bring the most consistently clean air of the year, while summer heat waves, often worsened by haze drifting in from other regions, bring the year's worst air. Coastal sea breezes can offer some relief from inland summer ozone buildup.
Are air quality levels in Norwalk 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: 9 August 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.
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