Worst air pollution Castine, today and tomorrow
Today (9 August): Air quality in Castine is medium. AQI and O3 are medium; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 9:00 AM (O3: 40.9/100).
Tomorrow (10 August 2026): Air quality in Castine is fair. AQI worsens to fair; O3 increases to fair; all other pollutants stay as today. Pollution peaks around 11:00 AM (O3: 34.0/100). 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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Castine's air quality is shaped largely by cool coastal Maine air; onshore breeze keeps air quality consistently clean. Overall, Castine sees air quality that tracks fairly closely with typical conditions for its wider region. Visitors and residents alike tend to notice the clearest air outside the warmest summer weeks.
Today - 9 August | Pollution peaks at 09:00
AQI:
Medium
40.9/100
PM2.5 (fine particles):
Good
8.0/100
PM10 (coarse particles):
Good
5.5/100
NO2 (nitrogen dioxide):
Good
0/100
O3 (ozone):
Medium
40.9/100
SO2 (sulfur dioxide):
Good
0/100
CO (carbon monoxide):
Good
0/100
HCHO (formaldehyde):
Good
10.2/100
PM1 (ultrafine particles):
Good
5.5/100
Levels show the poorest local air quality during the day
Tomorrow - 10 August | Pollution peaks at 11:00
AQI:
Fair
34.0/100
PM2.5 (fine particles):
Good
5.7/100
PM10 (coarse particles):
Good
3.8/100
NO2 (nitrogen dioxide):
Good
0/100
O3 (ozone):
Fair
34.0/100
SO2 (sulfur dioxide):
Good
0/100
CO (carbon monoxide):
Good
0/100
HCHO (formaldehyde):
Good
7.3/100
PM1 (ultrafine particles):
Good
4.0/100
Pollen forecast in Castine
View pollen forecastFrequently Asked Questions
Is air quality bad in Castine right now?
On 9 August 2026, overall air quality in Castine is medium. AQI is the main air quality indicator at 40.9/100. Pollution peaks around 9:00 AM (O3: 40.9/100).
Will air quality be worse tomorrow in Castine?
On 10 August 2026, air quality conditions in Castine will be worse than today, with AQI forecast at fair at 34.0/100. Pollution peaks around 11:00 AM (O3: 34.0/100).
When is air pollution at its worst in Castine?
Conditions in Castine vary noticeably across the seasons — spring and autumn generally bring the cleanest air, helped by more active weather patterns, whereas summer heat and regional haze drifting up from the Midwest and South drive ozone spikes. Winter cold fronts tend to clear the air quickly, so extended pollution episodes are relatively uncommon.
Are air quality levels in Castine 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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