Worst air pollution Williamsport, today and tomorrow
Today (9 August): Air quality in Williamsport is fair. AQI, NO2, O3, and PM1 are fair; PM2.5, PM10, SO2, CO, and HCHO are good. Pollution peaks around 11:00 AM (O3: 35.1/100).
Tomorrow (10 August 2026): Air quality in Williamsport is fair. AQI improves to medium; PM2.5 increases to fair; NO2 decreases to medium; all other pollutants stay as today. Pollution peaks around 1:00 AM (NO2: 45.7/100). Airmine updates local air quality forecasts four times daily.
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The dominant factor behind Williamsport's air quality is humid central Pennsylvania river-valley air; valley humidity can trap summer haze close to the ground. None of this is unusual for a place with Williamsport's particular geography and climate. Longer-term residents of Williamsport tend to plan outdoor activity around these predictable shifts.
Today - 9 August | Pollution peaks at 11:00
AQI:
Fair
35.1/100
PM2.5 (fine particles):
Good
19.5/100
PM10 (coarse particles):
Good
6.1/100
NO2 (nitrogen dioxide):
Fair
33.4/100
O3 (ozone):
Fair
35.1/100
SO2 (sulfur dioxide):
Good
6.6/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
4.2/100
PM1 (ultrafine particles):
Fair
21.4/100
Levels show the poorest local air quality during the day
Tomorrow - 10 August | Pollution peaks at 01:00
AQI:
Medium
45.7/100
PM2.5 (fine particles):
Fair
20.4/100
PM10 (coarse particles):
Good
10.4/100
NO2 (nitrogen dioxide):
Medium
45.7/100
O3 (ozone):
Fair
32.4/100
SO2 (sulfur dioxide):
Good
6.6/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
4.5/100
PM1 (ultrafine particles):
Fair
22.0/100
Pollen forecast in Williamsport
View pollen forecastAir quality forecasts for neighbourhoods and landmarks in Williamsport
Frequently Asked Questions
Is air quality bad in Williamsport right now?
On 9 August 2026, overall air quality in Williamsport 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 Williamsport?
On 10 August 2026, air quality conditions in Williamsport will be similar to today, with O3 forecast at fair at 32.4/100. Pollution peaks around 1:00 AM (NO2: 45.7/100).
When is air pollution at its worst in Williamsport?
Williamsport follows a fairly predictable seasonal air quality pattern: once summer ozone season ends, winter typically offers the cleanest air, but 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 Williamsport 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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